Police are warning of a shopping scam targeting residents in southwest suburban Palos Park.

Residents targeted in the scam have received checks in the mail for thousands of dollars to be used for a “secret or mystery shopper” service. Residents receive a letter with the check, instructing them to deposit the check, wire some of the money back to the company, keep some of the money as payment and use the rest to shop, according to Palos Park police.

Though the checks may appear legitimate at the time of deposit, they later bounce. The person who received the check is then left responsible for the money wired, police said.

Anyone with information about this scarm is asked to call the Palos Park police or contact the U.S. Postal Service.