A man walks into a room

And he sees a man sitting in the middle of the room busy sawing a piece of wood with his hand.
He looks up and sees another man dangling from the ceiling upside down.
"What are you doing he asks the man on the floor?"
"Are you stupid? I'm sawing this piece of wood in half"
The man replies: "And your friend hanging from the ceiling?"
"Isn't it obvious? He's a lightbulb" Responds the man sawing the wood.
"Well tell him to get down before he hurts himself"
The man sawing the wood stops abruptly and responds:
"And work in the dark?!!"