It's interesting to see what Burnt State mentioned about sleep deprivation being a possible factor.Looking back on my experiences they have been during periods that I've been working stupidly long hours.I'm currently over doing it again and my dreams when I do sleep have been highly disturbing and extremely vivid.(Though no sleep paralysis episodes). On a side note I was staying over night in a small hotel last week.At dinner I got talking to a guy who was in a similar business to me,As we finished our meals around the same time we ended up returning to our rooms sharing a lift (Elevator) and discovered our rooms were next to each other.The following morning he commented about the late phone conference call I'd had.I had gone straight to bed and hadn't spoken to anyone.He was adamant that he'd heard 2 men's voices coming from my room and that neither voice sounded like me.I've no idea what he heard,I'm usually a very light sleeper and the t.v. wasn't even plugged in to have been on at any time.I do fall asleep listening to a white noise app but don't see how this could be construed as two voices.It's another mystery I will never solve.
I think sleep deprivation has a lot to do with it i had some bouts of this during my time in Afghan and Iraq, felt strange and seem like something was sniffing me.
also had a few reports of some friends who also suffer from this Phenomena what extremely tired but on a few occasions "Shadow Men" or BEINGS were also present.