"How are you going to do that?"

"Watch," he said, and climbed up on a rafter.

The foreman asked what he was doing up there, and the man replied. "I'm a light bulb."

"I think you need some time off," the foreman said, and the first man walked out of the factory.

After a moment, the second man followed him.

"Where do you think you're going?" the foreman shouted.

"I can't work in the dark," he said.