Me and my friend Jacob were playing in my basement with all the lights off and only the smallest gleam of light. I was standing behind a hot water heater and Jacob was coming toward me, but he was crouching. I couldn't see him, and didn't know he was there, but then I saw a shadowy figure slowly walking through the doorway to my right, and the air around me got cold, I thought it was Jacob, and I was going to turn and scare him, but didn't. Then I heard this big bang in front of me and it was Jacob crouching on the floor, he had slammed his hand on a drier, and he was there the whole time. He said to me that he saw the same figure in the gleam of light a couple seconds ago. The gleam was in my sister's bathroom, so nothing could have gotten in or out.
For me, it was the scariest thing I ever saw.