Ever noticed that some electrical outlets have a red and a black button in the middle? You’re looking at a GFCI — a Ground Fault Circuit Interrupter. This sophisticated device senses any current leaking through and immediately shuts off the power so you don’t get a shock.

In newer construction, GFCI outlets are located wherever water and electricity are used in close proximity: near sinks, in the garage, and at exterior outlets. In an older home, there may be a GFCI breaker (with push buttons) in the main electrical panel.

You should test this device every month to make sure it’s working to protect you from shocks. A simple test is to plug a lamp into the outlet with the light on. Press the “test” button and you should hear a click and the light should turn off. Push the “reset” button and the light should turn on with a click of the GFCI outlet.

Statistics show that about 10 percent of household GFCI devices are not working properly. If you find a problem, hire a professional to fix it ASAP.