I believe that the spirit world is our world, just the energy of it, and I believe its when we astral travel or become ghosts we walk through this realm, that is why it always seems theres a turn that is not there in some places, or writing on a wall that isn't there in this world, it is the energy of everything, sort of like the wire frame of a video game, and i do not believe that spirits or well not all of them are out to get us, I think most would like to just have corporeal bodies...in my opinion again, and all of the spirits come from different realms, and ours is at the center of it all, the nexus, thats why No one can just march up to the heavens, they have to battle there way through here first. But like many have said, they just want to live here and have a slice of the pie for the most part, I mean don't we all?