We're discussing something similar on the MT list at the moment. I'll add my two
cents at both places.
I think of a ghost as either being an earthbound astral fragment that won't let
go of it's earthly ties, or an energetic imprint from an emotionally charged
event that left a psychic impression in the terrain. In such cases, the haunting
is really like a holographic projection created by the emotional intensity of
individuals who have long since departed. I'm not entirely sure how it works,
but this projection plays back in an endless loop, perhaps gradually fading in
time like the decay rate of a radioactive isotope, to offer a comparison. The
haunting is no doubt perceived by those sensitive to such activity. That's pure
speculation on my part, of course.
So, in short, Michael is not a ghost. They're what we call an entity, which is a
united group of 1050 souls. They emanate from a spiritual plane known as the
Causal. You can find more information about this at michaelteachings.com
Best,
Dave