Yesterday, while driving, I heard about Border Blasters on the radio. Dave Davies was interviewing author Bill Crawford about his book Border Radio: Quacks, Yodelers, Pitchmen, Psychics, and other Amazing Broadcasters of the American Airwaves.
It is a fascinating (real) story about these radio stations which would transmit into the US from across the Mexican borders. Apart from their unusual content, these radio transmitters were so powerful that the broadcast could be heard as far as east Asia. Bill Crawford was saying that some of these transmissions could be heard by people on their dental work. I have heard of other cases where people heard radio transmissions on their dental work.