You're looking to pull in a bit of extra income and so you put up your house or condo for rent as a vacation property. One day, you get a request from a gentleman requiring the apartment next month for a business trip. He sends you even send you a cheque in advance.
A couple of days before he is supposed to show up he calls you and say that, unfortunately, the trip has been called off.
You are disappointed to say the lease, since you had to turn down other rental offers, but he apologizes and suggests you can deposit his check and wire him back all but 10% for your troubles. You do so, and the cheque bounces a few business days later. You end up basically the same as you were, minus the few hundred dollars that you wired to him. So much for extra income.
How to avoid: wait until a check clears before counting it as your money, and always be sceptical of deals that involve wiring money.