The wire gauge for a 110-volt system depends on the amperage of the system and can range from 0 to 22 gauge. The typical appliances in a home function at 15 to 20 amps, which correlates to a 16- to 18-gauge wire.
As all systems are different, it is important to confirm the amperage of the electrical units in use before determining the wire gauge. Incorrect wiring can lead to malfunction of the system. Additionally, the wire length needed will affect the conductivity of the wire, and the gauge may need to be increased so that the voltage remains steady.