I received a letter. I had won some lottery!

I didn't get a call, rather I got a letter not about a lottery, but about shadow shopping. Same guy Stanley Washington. Of course there is no number you can reach him at that is in the states. He sent a check for $4,985. The red flags that went up was when I saw that the check was from California, but the envelope as well as the stamp said Canada. So Bank of America has a big part to do with this scam. As well as www.shadowshopper.com. How does that work that www.shadowshopper.com can be a scam if they have upgrade options and real job offers on there?