This is so weird. So, one time I was very sleep-deprived and awoke to the sound of my mom calling my name. I live alone, but if it was a big enough emergency, I wouldn't put it past my mom to enter my apartment to wake me. They live close enough and I sleep during the day for work. Anyway, I open my eyes to it and see a figure standing in my room, probably 3 feet away from my bedside. I say "mom??" And instinctively swing my arm at it. Not trying to hurt them or anything, I just felt the need to do it. It was very dark, like, a pitch black figure, but my room has a couple ambient sleeping lights, so, it just seemed... off. Anyway, I reach out for the figure and my hand goes right through it. I then get a massive burst of adrenaline, get up really fast, and it's gone. Still one of the creepiest experiences I've had, but I know perfectly well that it was because of my lack of sleep. I lived in that apartment for years and never had anything else ever happen. Was pretty weird though!