If someone you don’t know sends you a check and asks for money back, that’s a scam.
Fake checks drive many types of scams — like those involving phony job and income opportunities, online classified ad sales, and others. In a fake check scam, a person you don’t know asks you to deposit a check – sometimes for several thousand dollars and usually for more than you are owed — and send some of the money back, often by wire transfers or gift cards, to them or another person. The scammers always have a good story to explain the overpayment. They might say they’re stuck out of the country, they need you to cover taxes or fees, you’ll need to buy supplies, or something else.