" Attachment theory is the belief that a spirit becomes attracted in some way to a living human and begins to coexist with (or even within) that person. It is believed these spirits find something comforting about someone and attach themselves to the person. Living people who share a building with the spirit of a deceased person can develop a relationship, and the spirit becomes intertwined in the life of the living. "

― Zak Bagans , Dark World: Into the Shadows with the Lead Investigator of The Ghost Adventures Crew