Explanation: Water, water everywhere, but not a drop to ... shower in? The National Weather Service urges the public to avoid hopping in the shower during a lightning storm in the event that a bolt strikes one of your home's water pipes and electrifies your bathroom.
MythBusters Jamie Hyneman and Adam Savage took that weather alert to task and constructed a makeshift house, complete with grounded plumbing. Then, they doused it with simulated lightning in an electricity testing facility to find out whether the voltage really could leap from the sky to the shower.
Since the MythBusters were shy about showering on camera, they hired a stand-in: a ballistics gel dummy that had roughly the same electrical conductivity as the human body. To screen for a fatal lightning strike, the dummy wore a heart monitor. The 700,000 volts of fake lightning indeed arced onto the water pipes and jumped to the shower, causing a fire.
Although the heart monitor failed to measure the amount of current swimming through the stunt dummy, the visual evidence was clear enough to rule the myth plausible. Just as the National Weather Service warns, it's safe to shower only once thunderstorms have passed you by.