Thanks. I'm just using raycasts. When the ghost haunts something the object sends a raycast and if it his a person facing it they panic. Also the people have a raycast in update and if they come across a haunted object they'll get nervous for a few seconds and reset it. If they come across another haunted object while nervous they panic. You have to scare everyone who lives in the building before time runs out and there will be other people like paranormal investigators and priests who try to slow you down and stop you.
My philosophy on this stuff is just get it done as quickly as possible. It can always be changed later.
What are you working on? It sounds like you're doing something similar? I'm looking forward to trying it out.