I agree with the exploding head thingy.
I've also been harping on about hypnopompic hallucinations somewhere else on the board just recently, so won't go into that here.....but! I do have a few past examples of my own to share, which intrigue me to this day...
One of them occured at a previous address. Up to three or four weeks before I moved out, I was regularly woken by a knocking sound. It sounded exactly like a human knocking on wood - not a random series of sounds, more a certain rhythm, like many people often have a 'signature' knock when they come to visit. Due to this I ruled out rodents, pipes, house settling, etc, and it only tended to happen during the night.
All my neighbours and I had pvc doors, and there was nothing else in the vicinity to explain it.
It occurred about once a week at different times of the night and wasn't always the same 'rhythm' - it varied slightly but still had the impression of a loud, determined 'human' kind of knock.
I explained it away as hypnopompic until I was still awake reading when it happened, and my cat, snoozing on the bed almost jumped out of his skin. I did go outside to explore but found nothing.
A short while later, at my new address I would wake in the night to a terrifyingly loud crash, as if someone has kicked the front door in or else smashed through a window. This began the very night I moved in, and again several times this occurred when I was not already asleep. I lived alone at the time although a family member occasionally slept over - and she was woken by it too! Yet in her case, at the back of the house she was woken by what sounded like large stones or clods of earth hitting the bedroom window. Nothing was ever found after searching for a source to the sounds.
An otherwise positive-feeling home, although I never did sleep well in all of the 4 yrs I stayed there.
I haven't experienced anything like it since.
It may be relevant that the first set of disturbances happened quite close to the death of my father, and a fair amount of personal stress followed me to the next property. Still, being awake on a number of occasions, and having a guest witness it doesn't hold too tightly with the hypnopompic theory, so make of that what you will!