Again, the only way to contact the owner, is to put a notice on the door, as well as send a letter to them. The post office may have a forwarding address that the notice is sent to.
There are various sites that allow you to try to search further to locate a person, but I'm not familiar with them. At this point, you don't know if the person is even alive, when you say the home has been deserted for many years. You may want to check if their taxes are current or if utilities are currently on at the property and who is paying them. Sorry, but there's no specific, guaranteed way to locate the owner.