Beware of Dog!
Upon entering a small country store, a stranger noticed a sign saying DANGER! BEWARE OF DOG! posted on the glass door.
Inside a harmless old hound dog was asleep on the floor beside the cash register.
The stranger asked the store owner, "Is that the dog folks are supposed to beware of?"
"Yep, that's him," the owner replied.
The amused stranger inquired, "That certainly doesn't look like a dangerous dog to me. Why in the world would you post that sign?"
"Because," responded the owner, "before I posted that sign, people kept tripping over him."