Just to preface this. I don't really believe in the paranormal, Ghosts and such seem unlikely and most "haunting's" have logical explanations. That being said though I have a few good personal stories that fit the bill
Puddle of Blood:
So me and my partner had moved into our current house and been there for a couple of months. One night she wakes me up in a bit of a panic because there is a pool of blood on her pillow, probably about the same size as the palm of my hand and still wet, it is also down the side of her face where she was laying in it.
At the time my daughter was still sleeping in our bedroom in a cot so we go out of the room and I clean her face really carefully looking for where the hell all this blood has come from. I do have some "advanced" first aid training so kind of know what to look for. There is no blood in or around her ears, nose, mouth or eyes, just on her cheek and jaw where she laid on it.
I spend quite a long time checking through her hair, her neck, even her hands and arms. Cant find a single mark on her or any signs of blood except that on her cheek. She hadn't been coughing or vomiting so wasn't internal and even then for the amount of blood I would have expected to see it on her lips/mouth if it was.
I even checked the roof/ceiling and mattress to see if something had maybe leaked but don't find nothing.
This was several years ago and never happened again since. The next morning I checked her over again during the day but not a single mark on her. We have absolutely NO idea where this blood came from.
Kids are freaky:
Same house, this was maybe a year ago, my daughter is 4 now and in her own room. We still have a camera/monitor in her room because she sleeps one floor above us and we are both heavy sleepers.
Anyway about 4am she calls out for Mommy. Mommy goes up to see if she is ok and I'm listening over the monitor.
Daughter: "Mommy, why does my light keep coming on it woke me up"?
Mommy: "You mean the red light on the fire alarm?"
Daughter: "No, My big light, it is making shadows on the walls."
Mommy: "you must have been dreaming lovely, go back to sleep".
Daughter - Looking past Mommy at the partly open bedroom door "Who is that outside in the hall?"
Mommy: "Nobody lovely, everyone is asleep".
Daughter: "No Mommy, there is, they were poking their head around the door, their face was white".
Daughter: "Can I come sleep with you and Daddy"?
Mommy -"Yes, yes you can, lets go".
I've got quite a few more, will post them up when I get time.