Ground fault circuit interrupter (GFCI) can help to prevent electrocution and electric shocks. The National Electrical Code, or NEC, has specific GFCI requirements for dwelling units. Article 210.8 states that ground-fault circuit interrupters shall be used for all 125-volt, single-phase, 15- and 20-amp receptacles installed in bathrooms, garages, outdoors, unfinished basements, crawl spaces, kitchens, laundry rooms, pool/spa areas. A DIYer with knowledge of electrical wiring may be able to replace an existing outlet with a GFCI outlet, but only when swapping out a three-prong outlet—two plugin slots and a hole. Outlets with only two slots and no third hole indicate the presence of older wiring that should only be replaced by a licensed electrician.