Actually if the home is in Kent County you can go to http://www.accesskent.com
and find out who the owner of record is and contact them. There are a variety of scenerios for this home. It could still be in the foreclosure process and the lender put a lockbox on the property because they needed to protect their asset now that it is vacant. It could be for sale but if it was there would most likely be a some sort of sign in front of the home to indicate it is currently on the market. You could call the number listed for emergencies but normally they don't give any information out.
If I can help in any way please let me know. I deal with lender owned properties a lot.
Have a great day!