This is bizarre story from World War II! In 1942, Lucille Ball, actress and future star of I Love Lucy, had several lead fillings put in at the dentist. Afterwards, she was driving home late one night from MGM Studios and started hearing music coming from her mouth. A co-worker told her that she was picking up a nearby radio station and that he knew someone else who had fillings and experienced the same thing.
A few days later, she was driving home a different way from work and began hearing short beeps that sounded like Morse code. She reported it to the FBI who searched the area and found a Japanese underground radio transmitter. It was hidden in a tool shed that was used by a Japanese gardener, who turned out to be part of a spy ring operating on the West Coast!
Listen to Lucille Ball herself tell the story in this 1974 interview with Dick Cavett. History can be amusing!