I remember one time I was upstairs late at night getting a drink from the kitchen when I heard my little brother talking down the hall. I stepped out of the kitchen to see what he was doing and found him standing at the sliding glass door right outside his room, with the door open, talking to what I assumed was himself.
As I approached I heard him say, “NO! You can’t come in here.” Since I couldn’t see well in the dark, I asked who he was talking to. He turned to me with his eyes half open and said he was talking to, “the man outside.”
Freaked me the fuck out. I closed the door and put my little brother to bed then went and hid under my covers for the rest of the night.