GFCI OutletGround-fault circuit interrupters, or GFCIs, are safety devices that are put on electrical outlets, also known as electrical receptacles. They’re also located on extension cables, circuit breakers, and other electrical equipment.

When the low-resistance grounding route from a tool or electrical system is broken, a ground fault occurs. The electrical current may then take a detour via the user to reach the earth, causing significant damage or death. The ground-fault circuit interrupter, or GFCI, is a fast-acting circuit breaker that may cut off electric power in as little as 1/40 of a second in the case of a ground-fault. It compares the amount of current traveling to and coming back from equipment along circuit wires. The GFCI stops the current when the quantity going exceeds the amount returning by around 5 milliamperes. GFCI’s protect against the most common type of electrical shock hazard.

Article 210.8 of the National Electrical Code (NEC) recommends that GFCI protection be provided for all 125-volt, single-phase, 15- and 20-amp receptacles in the following locations:

Bathrooms
Because water is usually present, your bathroom is a high-risk place for electrical shock. All of the outlets in this room should be GFCI-proof.

Utility and laundry sinks
Electric-powered washing machines (washing machine and dryer) are located in your laundry room. If the receptacles are within six feet of the external edge of your sink, GFCI protection is required.

Detached structures and garages
Even though they are not living spaces, detached buildings like sheds should be GFCI protected. The garage should also have GFCI protection.

Outdoor receptacles/outlets should be GFCI-protected

GFCI ProtectionElectrical circuits and receptacles near a spa or pool
Because pumps, fountains, and other water sources can be found in your pool and spa room, GFCI-proof outlets should be installed within 20 feet of your pool, water fountains, and spa.

Basements that aren’t finished
Unfinished basements, like crawl spaces, are portions of your basement that are not inhabited or lived in. These spaces should be protected.

GFCI protection is required for receptacles in these places to avoid moisture damage to appliances and to protect the occupants of the home. The only time this rule does not apply to basement GFCI protection is when the systems powering equipment receptacles are permanently fastened or not easily accessible. An example would be a security or fire alarm.

Kitchen Countertop Surfaces
Receptacles that serve countertop surfaces should be protected. GFCI protection is also required for dishwasher outlets. Also, the receptacles that are within 6 feet of the top inside edge of the bowl of the sink.

You can find information about how to install a GFCI receptacle here:

https://www.youtube.com/watch?v=Uop79H_iqoQ