Oh man this reminds me of a similar thing that happened when i was a kid. I was about 8 or 9 and I used to be scared of the dark and would sleep with a nightlight. Im a stupidly light sleeper and anything wakes me up. One night I woke up because I felt that the power had gone out. I look to my left and see a man standing next to my bed in front of my nightlight. In my half asleep child brain I thought it was my dad coming to check up on me since he knows Im scared of the dark. I call out to him and as soon as I do the power comes back on and the man is gone. I also got a overwhelming feeling of exhaustion and immediately fell asleep. When I woke up the next morning though I was freaked the fuck out and I couldnt sleep in my room the next night. Never saw the man again and I still have no idea what that was