koima57: I think it's a firefly, in a small room with left out furnitures all over, the door has something written on it, and is located to the right of the school main door, very early in the demo.
It's been bugging me too.
The problem is that the pesky insect constantly interrupts Linda's actions because she instinctively starts flailing her arms about trying to get rid of it, but alas to no avail. You can't outrun it, you can't lock it in a room and the cat doesn't feel like chasing it.
Never mind the ghosts... it's the damn insect that has me living on my nerve ends.