How to Track Down an Owner When The Ph. Numbers at TLO Dont Work?

[Burt L.]

I saw a boarded up house in a very valuable are, and its owners address is listed at the same house.

When running a report at TLO, it gives me phone numbers that don't work, and there are no other previous addresses or relatives still living, in the TLO report.

 I have hit a dead-end here. Have you any other suggestions on how to reach such a person? I haven't knocked on doors as someone is doing a flip right next door and I want to create competition. I have also seen Sean Terry's suggestion of putting a "for sale" sign in the front yard, until the unhappy owner calls to see why you are selling his house, but my phone would blow-up on this house.

Any other ideas on tracking people down? I don't know if a private detective could get better info than TLO.