Overpayment, then a refund
A buyer sends more than you asked for.
A cashier’s check, a money order, sometimes a convincing screenshot of a transfer.
Then they ask you to wire the difference back — often to a shipper, or somebody else entirely.
The original payment fails days later.
A bank accepting a check is not the same as that check clearing. By the time anyone notices, the money you sent back is gone.