About 6-7 years ago I was living in Maryland with my grandparents. They had this huge old estate home with white clapboard siding, dark shutters, and it was two stories high and had about 8 rooms. At the time my aunt and her three young kids were living there as well.
In my room I had my own bathroom so, because it was kind of squeezed in there, it made this hallway between my bedroom and the actual bedroom door. This one night I was lying in bed attempting to fall sleep but really just tossing and turning and when I turned towards the bathroom and bedroom hallway I saw the black shape of head and shoulders sticking out from the wall.
At the time I didn't know this was a shadow man and I'd never even heard of them but what made mine different from the ones I've read about is that he had an oval shaped white face with only black holes for eyes and a mouth. If you've ever seen that anime movie 'Spirited Away' the shadow I saw looked exactly like the character 'No-Face' from that movie. I know a lot of people will think I'm making this up or pretending that I saw No-Face but I swear that's what he looked like. Anyway, as soon as it realized I'd seen it, it ducked really fast and just sort of morphed into the wall and disappeared and I mean fast.
I've never seen anything else in my life move that fast not even a cockroach or any kind of animal. And also the mass of the shadow is hard to explain because, although I somehow knew it wasn't solid, the black was SO black, darker than the night of my dark bedroom around me. I was kind of in shock so I kept staring at the spot and I saw it dart out and then back in really fast one more time and then it stopped for the rest of the night.
But what really drove it home for me was the next day while I was babysitting my aunt's kids. I told the youngest one, a boy, to go in his closet and pick something to wear and he started crying saying he didn't want to go in there because that's where the 'white man' is... So I made him explain to me what he was talking about and he described the exact thing that I had seen the night before. He especially mentioned the white face/black eye holes thing...
I would also experience random blackouts and unexplained knocking frequently while home alone in that house.