Fright Night

I work nights.
In a big old building.
Alone.
(Yes, by myself).
On the top floor.
There is an attic.
It is windowless.
Pitch black.
It has one bulb.
Hanging, on a wire.
And many unlit corners.
I don't go up there.
I've seen the films.
I know the score.
My blip is the sign.
On the attic door.
No one sees the problem.
But I do.
Do you?
Goodnight.