We live in a holographic universe. From memory 97% of our DNA's...

We live in a holographic universe.
From memory 97% of our DNA's role is to be sender and receivers of energy, some guy won a nobel prize for finding that out.

Also all matter is energy condensed.
Put those two together and you realise everything is just energy, these 'ghosts' IMO are just energy on a waveform not as condensed as us.
(in short I don't real know but these is some evidence on this and photon tests)

Other than that I don't really know much more but Sean Stone son of the famous movie director Oliver Stone talks about ghosts and satanism and what it actually is:
http://www.youtube.com/watch?v=0lrbeUK0lI0

It's what some would refer to as Satanism. From all reports, including Sean Stone, that's what the elite are into and he knows people that do it. That's why they do all the crazy rituals they do like at Bohemian grove, Skull and Bones, and at their retreats.

I never believed this stuff till recently being open to it. It appears this stuff usually happens just outside of our visual spectrum. Hence why certain natural drugs let people see spirits, which most indian and shaman tribes talk have talked about for centuries.

David Icke (among many others) cover it too on how these entities exit just outside our visual spectrum. Mostly in regards to his talks on what he calls 'reptilians'.

Hope this helps further your investigation.