While the labyrinth of wires that runs through the inner recesses of a home may seem to most people to be a tangled mess, they are—in order to function safely or at all—a precisely organized system.

A home’s electrical system is made up of a number of circuits. A “circuit,” by definition, is a circular journey that begins and ends at the same place, and this is essentially how electricity works. Current begins at a power source, powers the appliance or device along the circuit, and then returns to the power source. Any interruption in this path will render the circuit dead.

Illustration copyright Sunset Publishing Corporation