When i was a kid. Maybe 7 or 8 I'm not sure anymore. Woke up in the middle of the night to see a shadow in the doorway. It looked like my sister, but just the silhouette. And it wasn't like it was her in the dark, it was just this black hole shaped like her. Sometimes she would sleepwalk and wind up in bed with me in the morning but this was definitely not her. I couldnt move and was totally paralyzed with fear. I just kept staring through the dark at the shadow and it just stood there in the open doorway unmoving. I finally was able to raise my hand and managed a feeble little wave with my fingers- to see if it was her, to say hello. The shadow raised its arm like it was going to wave back but it just left its hand hanging in the air. I managed to very slowly pull the covers over my head and just waited. Guess I fell back asleep eventually. Not sure if this was a hypnopompic hallucination or sleep paralysis, but when I first woke up I definitely couldn't move and was transfixed on the shadow in the doorway. Thanks Reddit, haven't thought about that one in years.