On the glass door of the little country store, the stranger noticed a sign saying: DANGER! BEWARE OF THE DOG! Inside he noticed a harmless old hound dog asleep on the floor next to the cash register. He asked the storekeeper, "Is THAT the dog we are supposed to beware of?"
"Yep, that's him," he replied.
The stranger couldn't help but laugh. "It certainly doesn't look like a dangerous dog to me. Why in the world do you need that sign?"
"Because," the storekeeper replied, "before I posted that sign, people kept tripping over him."