The letter looked both enticing and phony.
"I'm a winner of $50,000.' said Lisa Baravish of San Bruno.
The letter said she had just won a big cash prize in a drawing by several major retailers.
"The thing that makes it, I think enticing to people, is it has Walgreens, Safeway, Sears. You know, stores that people shop at," said Baravish.
All she had to do was cash a check for $2,400 and use it to pay a $980 tax, then FedEx would deliver her a big prize.
"And at first I went, 'Oh this is pretty cool,' and then, 'Yeah right, who's going to give me $50, 000,'" she said.
Baravish suspected a fraud. So she called the bank. Sure enough, the $2,400 check was a fake. If she sent the $980 it would have come out of her pocket and gone right to the thieves.
"But I thought it would be interesting to play along," she said.
So Baravish decided to catch a thief. She called the number in the letter and a man picked up. He told her to cash the check and call back.
"And he said, 'Oh, ok, did you cash it,' I said, 'Oh absolutely I cashed the check.' And he said, 'Oh, ok, well you need to go to Walmart now," said Baravish.
The man wanted Baravish to buy a $980 money order from Walmart, and then call back again.
When she called back, the same man picked up and asks for her reference number. The man told her to call back the next day and one of his associates would tell her where to send the money.
"He said FedEx will come to my door but I'm to call after I get the check to get more directions," said Baravish.
Instead, she went online. She found that dozens of potential victims received the same letter, the same fake check and same phony contest.
"Finally I said how come there's no money in that bank that you sent me the check on and [click], he hung up on me," said Baravish.
The letter had all the classic signs of a mail fraud. It claimed you won money. It provided a check that looks real and it says to use it to pay a fee. If people deposit the check, their bank will credit their account at first. But when it comes back as fake, the money comes right back out of your account.