with my mother and she was withdrawing some money from her account and the teller gave her one of those withdrawal slips back with her money. When we looked at it we saw it wasn't hers at all, apparently the teller gave back a slip that belonged to the customer that came ahead of us. It had her name, account#, SS#, and deposit amount (over a grand) on it. There was enough information for someone to not only wipe her out but come back for more later, plus it's the first of the month so she probably just deposited her SS check as the woman in front of us was elderly. If it had been anyone else I think she would have been robbed. Yes we will inform the teller of her mistake and destroy the slip. I want to tell a manager but I don't want the teller to get fired, but it was a big mistake. The point of all this? Have you ever done anything at work to get yourself fired?