This page gives diagrams of a typical home wiring circuit, showing both the cables as they might be run in the rooms (shown as a floorplan) and the wiring connections as they might be made in the electrical boxes. To view, open both
cables
and
connections
. I am not offering this page for the purpose of those who are doing new wiring in a house, but to help homeowners understand their system better, so they can troubleshoot malfunctions. A description of the portion I have called "Connections" above is found as
Tour of a circuit
.