Address Fraud

Started receiving USPS mail at my address off and on for the last few years from a possible former resident of 20+ years ago. Returned all mail "return to sender" but still is received. Contacted the Post Office to stop delivery of mail for this individual to my address.

Google name search shows this individual using my address as his primary address and not former address on some smaller less known name search web sites. Is this a red flag I should be concerned about?

Yes, I would consider this a red flag given the environment we all live it today. Specifically, theft of home titles and deeds to property red flags are my references. 

SA