Consciousness is energy, and new research is showing that it can exist outside the body...like near-death experiences. Sometimes, that energy hangs around awhile after someone dies, usually when the circumstances left a lot of unfinished life business for the person. In other words they are stuck, grieving....as in "Poltergeist". The little lady that was in the movie was a "soul retriever"....they intervene in the psychic realm to let the spirit know that it can move on...to release it.
Now that the Russians have better things to do than building nuclear missiles, they're making some interesting discoveries about human DNA
http://www.rense.com/general62/expl.htm
Matt. 17:20 "For truly I say to YOU, If YOU have faith the size of a mustard grain, YOU will say to this mountain, ‘Transfer from here to there,’ and it will transfer, and nothing will be impossible for YOU."
~PS