Summary:
  All forms of checks, money orders and cashiers checks can be fake.
Banks will put the money in your account and it may take weeks for a bad check to bounce.
  If you are selling to someone local (e.g. on craigslist) specify that they use a local bank and take the check there to verify it.

  PayPal scams usually involves sending extra money to pay a shipper who buyer is sending.
  You should ship it your self with a shipper who will track it and specify signature on receipt. PayPal dispute resolution will not let them cancel payment if you have documentation showing receipt.

They work on the fact that banks have to show a certain amount ($200 for a personal check or the whole amount for a cashiers check) as available in your account even though the check has not cleared thru the payers bank.
People who work in banks are not trained to understand that the banks computer system may show the money as available even though the check has not cleared and they will tell you the check has cleared.

They take a variety of forms.

• The scammer picks up the product before the seller finds out the check is bad.
  In many cases they have a fake shipping company (someone working with them) pick up the item.
• The scammer overpays for a service (e.g. vacation home rental) and asks you to send the difference back with a Western Union Money Transfer before you find out the original payment was no good.
  See Overpayment Scam

Unfortunately, the term "clear" sometimes gets used prematurely. An item has really only cleared after your bank has received funds from the check writer's bank.

It's best to ask for a check drawn on a local bank or a bank with a local branch. You can visit that bank branch to determine if the check is legitimate.

I got a bad check (below) from Citibank DE and went to a Citibank branch in NJ and told them I thought it was bad. They checked it out and said it was good and I could deposit it and open a new account to get a cash reward.
I faxed it to their security department and they said it was NOT good.

It's not clear exactly how long you should wait before spending the money, but you might want to wait at least 30 days. If the check is from a foreign bank, you should wait a little longer.

You might be tempted to ask your bank whether or not a check has cleared. While this is quite reasonable, it may not be as helpful as you'd hope. Bank employees often don't know exactly what your concerns are with the check, and sometimes they don't even know that checks can bounce long after they've been deposited. They don't understand the banks systems and assume if the money shows up in your account the check is good, which is not true. Sad!

If you're worried about bouncing checks, request payment in different forms. The safest way to get paid is via wire transfer. The money will only show up if it really exists, and the transaction cannot be reversed.
You can also ask for cashier's checks or money orders; just be aware that those documents are sometimes faked (so you can run into the same problems you'd have with a bad check).
See How Long to Wait After Depositing a Check?

• There is a black market for pilfered cashiers checks usually from a bank branch wich is closed.
• There is now software which will print phony cashiers checks.

Counterfeit cashier's checks supposedly issued by Patelco Credit Union are in circulation across the United States. Call 800.358.8228 if you get one.

See:
Office of the Comptroller of Currency OCC.gov: 2015 Alerts
Cashier's Check Fraud & Scams: How To Spot A Fake | WalletHub®

• They have not updated their credit or debit card information, so the expiration date has passed
• They have used their company issued credit card and their company did not authorize the purchase, and has disputed the charges
• They themselves have disputed the charges - and I'm not talking about the valid disputes, but the disputes simply because they can (they simply don't want to pay).
  If they have paypal set up to pay via a credit card, they can ask their credit card company to reverse the charge (a "chargeback").
• Someone in the household has purchased something without permission, so it is disputed.

Another paypal scam is send you a phony email indicating the payment has posted.
A legitimate email looks like this:

                   Hello, You


        John Doe sent you 
        $200.00 USD
    
            Transaction Details
    
Transaction ID: 5NB33326HN011491G    September 26, 2016
 
Money received                   $200.00 USD
 
                             Fee   $6.10 USD
                          Total   $193.90 USD

John Doe
Money Received               $200.00
OK to ship. What's next? Print shipping label | Add tracking info

I talked to PayPal's dispute resolution department. They said:

• Always have the buyer specify "Goods and Services" and not "Personal Payment" when sending the PayPal payment. That allows you to open a dispute process.
• Do not use their shipper/delivery service (usually someone working with them).
  Do you own shipping and specify that the recipient should sign for it, so you have tracking information to prove delivery.
• Buyers have 3 days to inspect an item and can then cancel payment if they claim it is defective. They must then return it. Paypal' dispute resolution department will ask for documentation.
• Buyers cannot cancel a payment claiming it was unauthorized use of their paypal account. It is their responsibility to keep their password secure.

eBay has their own escrow service for motor vehicles.
eBay has approved the use of escrow.com
Sites like Ebay-Escrow.com and secure-escrow.com are phony services.

See
Tips for Avoiding the Fraudulent Escrow Service Sc... - The eBay Community
Quick Tips for Escrow on eBay | TheBalance.com
Using escrow services for eBay Motors vehicles purchases

• Scammers often communicate with their victims using poor grammar/spelling or vague language. They may also refuse to meet in person or send an email or a text message indicating they're not from your area.
• There were lots of warning signs on the overpayment scam.
  The renter was in chicago, the UPS mailing label for the check was from an business in Philadelphia, the check was from Google in Calif. and a bank in Maryland, they wanted me to send the overpayment via western union money order to Atlanta.

I listed an Eathen Allen cabinet for $750 in craigslist (They go for $1,500-2,500 new). I got 15 responses; I'm still sifting thru them, but they may all be scams.
Most payments were PayPal, some personal checks, 2 cashiers checks, 1 money order and one certified check.
4 or 5 said they were adding a moving fee to pay a mover they were sending to pick it up.
I responded to a couple which I thought might be legit. One was going to send me money via paypal; I never got it; The other was going to mail me check. See (scam 4 below)

Me:
Yes It is in very good condition.
My PayPal is ...

Scammer:
Ok i am interested..I have a new appliances being delivered tomorrow and doctor appointments...so i will arrange for movers that will come for the pick up once payment clear.can they meet you tomorrow or next day?

Me:
Ok Monday would better for me cc

Scammer:
Eathen Allen cabinet - $750 (Martinsville) ..Hello! Do you have Still have it for sale? I'm Ashley

Me:
Yes It is in very good condition My PayPal is ...

Scammer:
Ok i am interested..I have a new appliances being delivered tomorrow and doctor appointments...so i will arrange for movers that will come for the pick up once payment clear.can they meet you tomorrow or next day?

Me:
Ok Monday would better for me cc

Scammer:
Just to let you know that i made the Payment and i was charge $420 for the movers fee, and i got emails from PayPal that the funds are out of my account.
kindly go through your inbox mail for notifications transaction from PayPal.so we can know the next step of action.
Await to hear from

Me:
Haven't seen anything in my PayPal account yet:

Full Name:
Address: Not P.O.BOX
City:
State:
Postal Code:
Total amount for the item
Phone Number: That i can send text

I will make arrangements for the pick up as soon as you have your check clear, due to my work frame and my Kids, I will not be able to come with the cash and pick it up myself , so my payee will mail the check and have someone pick up the item after the check clear., Reference to your List post am completely satisfied with it and the payment will be deliver within 24hours.. God Bless.

Overpayment scam

Note you are not responsible for shipping as soon as you have the check and have it cashed my shipper will be coming over for pick up.Hope to hear back from you soon. I will email you more on what to do? Once you have the check.. you don't have to worry.. ?

Full Name:
Address: Not P.O.BOX
City:
State:
Postal Code:
Total amount for the item
Phone Number: That i can send text

____________________________________________
I sent my address and got the following:
to me:
Good Morning...I just want to thank you for the honest and trustworthy you are having towards this transaction and i want to bring it to your notice that my payment will deliver to today via UPS courier service.... here is the tracking number provided (1Z2F0F090161425081) so i would want you to follow my instruction on what to do about the shipping freight and handling as i told you before that i have some item to pick up in your area and the pick up arrangement. Once you have the payment with you now just get it deposited and deduct your actual amount plus extra $50 for the running around you are having and get the remaining fund send Via Money-gram at Walmart to the Mover information below for them to come for the pick up in your location since their freight and handling fee is been included with your money.. here is their information to get the funds send Via Money-gram :

Receiver's Name:- ....  .........
City:-  Dallas
State:-  Texas
Zip Code:- 75201

Thanks, as i wait to read from you soon

Note:
The name on the email, the UPS shipping label and check were all different.
The address on the check, Wellington, FL, was over 150 miles from the address on the UPS label, Orlando FL, and money was to be wired to Dallas.

I took the check into my local Wells Fargo branch and they said the numbers and the signature on the check looked OK. The teller supervisor said the only thing suspicious was the paper did not seem to be check quality.