A modular wiring system and method. At least some of the illustrative embodiments are systems comprising an electrical box having a first side wall, a second side wall and a back, and an opening through the first side wall (the side walls and the back define an internal cavity). The system further comprises an electrical backing insert comprising at least six electrically conductive paths, the at least six electrically conductive paths extending from a first end of the electrical backing insert to at least a medial portion of the electrical backing insert. The electrical backing insert is releasably coupled within the internal cavity, and wherein the at least six electrically conductive paths on the first end of the electrical backing insert are accessible through the opening on the first sidewall.