The good lights
A customer walked into the store looking for Christmas lights. The clerk showed her their top brand, but — wanting to make sure each bulb worked — she asked him to take the lights out of the box and plug them in.
He did, and each one lit up. “Great,” she said. The clerk carefully placed the string of lights back in the box. But as he handed them to her, she looked alarmed. “I don’t want this box,” she said. “It’s been opened.”