Any theories to share?

I am curious if anyone has any theories they wish to share concerning the concept of ghosts involving a connection with possible other-worldly visits and even inter-dimensional travel?

We recently had an "impromptu" session that seemed to have opened up some doors to this train of thought so I am just interested to find out if anyone else has already explored this and if so, what information you have possibly gathered.

Could much of this actually be related in different ways? I am starting to think the answer may actually be yes! Please share!

Paul