While it might sound like something appropriate to a politically oriented forum this is actually a sleep disorder. An article is out discussing sleep disorders which are downright scary.
Nightmare disorder is one we are probably all familiar with but try some of these:
1. Hypnagogic and hypnopompic hallucinations which occur as you wake up or start to fall asleep
2. Exploding head syndrome is where you hear explosions inside your head as you start to fall asleep
3. Sleep paralysis syndrome is where you wake up totally paralyzed.
Check the article out and see what you are happily avoiding.