Yes, speaking of which, it is best to throw away any hair dryer in your household that doesn't have a GFCI (ALCI) in it's cord. Horrible tragic accidents have happened over the years and why have that risk in your house. Old hair dryers should be discarded. Here a reprint from the web...
Appliance Leakage Circuit Interrupters explained
The buttons are part of a device called an Appliance Leakage Circuit Interrupter (ALCI). All hair dryers these days have them, for good reason.
Many years ago, the appliance industry received reports of hair dryers electrocuting small children in the bathtub, according to John Drengenberg, consumer safety director at UL, which develops product safety standards. “They would try to use it as a toy,” he says.
When an electrical appliance that’s plugged in is immersed in water, electricity can leak out of it and shock you. Unfortunately, circuit breakers in your home react too slowly to protect against electrocution (they’re designed primarily to prevent fires). Manufacturers started outfitting hair dryers with ALCIs after UL mandated them. If the ALCI detects a change in the electrical current, it will cut power to the appliance within a few milliseconds.
Related: 8 Ways You Didn’t Know You Could Get an Electric Shock or Electrical Burn
“We don't recommend tempting fate and trying it,” by immersing a hair dryer in water, says Drengenberg. But if you do it by accident, “it should protect you.”
If the ALCI cuts off the power to your hair dryer, turn it off and unplug it. Then press the reset button and plug it back in. The test button allows you to cut off power manually. It also, as its name suggests, allows you to test that the ALCI is working. Just plug the hair dryer in, press test, and the dryer should stop working. (To get it working again, unplug it and press the reset button.) Hair dryer manufacturers recommend testing the ALCI before each time you use the device, though that might be overkill.
Today, portable hair dryers without a circuit interrupter are considered hazardous and can be recalled, according to the Consumer Product Safety Commission.