Actually, for the old gilman estate you need to capture about 25 ghosts( anywhere around town,not just at local hauntings) after u capture 10 u will get a notification that if u keep up you will get a special gift (the house) the other house across from that graveyard u get by signing up for the mysteryoligist at town hall but,u need a cat go through the mysterys and u will see one that says its cat only select that and do all the stuff ur FINAL gift is the mansion. Hope this helped as the two houses require two different things to unlock them... Happy hunting;)