Found a vacant house. Looked up owner info on Property radar, now what?

[Rita Temple]

My husband and I found a vacant house in our neighborhood.  It has overgrown grass and a vacant tag in the mailbox.  I looked up the info on Property radar and it says the house is not in foreclosure.  Estimated value is $222,957 and loan balance is $90,500.  It has the names of the owners, but of course the address is of the house that is vacant.  What are ways of contacting the owner other than google search and Facebook?  What next?