Complaint Review: Surveyshops@gmail.com

I filled out some surveys online. This survey came up for a "Shopper Assessor". A cashiers check was was sent to me within 2 days along with instructions as to what I was to do. I did not know that this was a scam until I was trying to send in my report regarding the stores to the e-mail that was in the letter and I called the phone number that was included on the letter.

I worked as a "Secret Shopper" years ago for Kelly services but I didn't receive a cashiers check and deposit it into my checking account and wait 24 hours to withdraw it and purchase gift cards. I received an e-mail tonight from Customer Satisfaction Feedback Follow-Up. I would like to know what I should do?