To ensure that your GFCI devices are in proper working order and actively protecting you from electrical shocks and fires, perform a routine inspection about once a month.
To test a GFCI outlet, get a light bulb and plug it into the outlet. Then look for the test button and press it. If the GFCI device is working properly, the light will go off and the reset button will stick out.
A light that stays on indicates that there is a problem with the electrical wiring. If this happens, you need to consult a certified electrician to fix the wiring.