Mystery shopping jobs do actually exist. But along with the genuine mystery shopping opportunities there is also the presence of scams. Misty shopping jobs are basically about taking on assignments that ask you to review certain places and products such as restaurants, stores etc. And while you can find assignments in your area be careful not to get scammed By some websites who will try to sell you information about Mystery shopping jobs.
This information is more or less available for free. You can find many resources tAaat allow you to find mystery shopping job offers. One such website is Volition.com.
Be vary of any offer that you find advertised in newspapers in help wanted sections and in unsolicited emails.
Never ever pay to receive mystery shopping job assignments. They are available for free.