Ok everyone! Putting this on a couple spots so everyone sees it! 
1. There's some stuff going on with characters INSIDE the house. Aka James, Ambrose, and Richard.
These characters are experiencing a strange occurrence! For reasons unclear to our investigators, these three can only be seen and heard by some of our characters
     >James and Ambrose cannot see or hear Richard. They can see and hear everyone else. They in turn can only be seen and heard by Alonzo. NO ONE ELSE CAN SEE OR HEAR THEM.
     >Richard cannot see or hear James and Ambrose. He CAN see and hear everyone else, and everyone else CAN see and hear him.
     >Alonzo can see and hear everyone, everyone can see and hear him.
     >Ferd, Val, and Dirk cannot see or hear James and Ambrose. They CAN see and hear Richard.
Those who can't see or hear someone also can't see them affect objects. If the unseen person picked up, nudged, or wrote on something then only those who could see or hear them would comprehend this happening. 
Alonzo is the exception. Everyone can hear and see Alonzo as he interacts with any unseen people. Only his end of the interaction though. Exe. If Alonzo where handed something by an unseen, it would suddenly appear in his hands to any who can't see the unseen person.

I know it's a wee bit complicated but pm me with questions, and trust me.