Call of Duty: Finest Hour
This whole Easter egg is just completely strange. In the campaign for Call of Duty: Finest Hour, there is actually a room which is just completely full of ghosts. There is no ceiling, just floating candles. The more the player walks around the room, the weirder it actually gets.
To find this room, the player must throw a grenade at a wall so that the door behind the wall is blown out of the way. The player is able to interactive with the furniture inside the room, including a toilet and a baby cot. If the player walks toward the cot, they will actually see the ghost of a boy sitting inside, until he flies away.