If you’re ever a contestant on Jeopardy and you’re asked what a GFCI is, you can respond by saying, “What is a ground fault circuit interrupter.” But knowing what GFCI stands for doesn’t mean you understand what it is. You’re not alone—the average homeowner is unaware of what a ground fault circuit interrupter does, but when your house’s ground fault is compromised, it can put the entire property, and your family, in danger.

A ground fault is an electrical path between a power source and a grounded surface. While all electrical devices and appliances are “grounded” to ensure they can be safely operated, devices can still lose their grounding and divert electrical currents to the nearest channel that provides a path to the ground: you. That’s why you need ground fault circuit interrupters in your home.

You’ve probably seen GFCI and never given them a second thought. They’re a common safety feature found on your electrical outlets that can be identified as two small buttons located in between the two sockets, the GFCI’s function is to constantly monitor the power current flowing through a circuit. At the first sign of a discrepancy between the current flowing into the outlet and the return current, it intervenes by shutting off the power to the outlet.