Right, well, the "shadow people" can certainly be characterized as
"phoney baloney crap". But at times uninformed individuals are at a
loss as to how to explain hallucinatory episodes or the sensing of what
seems a malevolent presence during episodes of sleep paralysis. A fair
number of folks have explained away such experiences as alien
abduction, presence of demons, etc. Art Bell aids in the perpetuation
of such bogus explanations.

http://watarts.uwaterloo.ca/~acheyne/intruder.html

Coping methods for those experiencing such episodes:
http://watarts.uwaterloo.ca/~acheyne/prevent.html