Wiring Diagrams for GFCI Outlets - Do-it-yourself-help This diagram illustrates the wiring for a circuit with 2 gfci receptacles followed by a light and switch. By connecting the switch to the load terminals on the last gfci, the switch and light are protected against ground faults as well. This gfci wiring method may be found in a bathroom or kitchen where the switch may be near a water source. How to Wire a GFCI Circuit Breaker | Hunker Wire a GFCI Circuit Breaker. Turn off the main breaker in the service panel and remove the panel cover. Check the circuits with your voltage tester to make sure that they are not hot. Pull out the old breaker and disconnect the wires. Verify that the GFCI breaker matches the circuit wiring.