The mechanisms by which fire environments may trigger electrical arcs in household wiring are often misunderstood. A thorough knowledge of these mechanisms may assist fire investigators to determine whether a given arcing event was the cause or result of a fire. In this study, both unenergized and energized cables were tested under a variety of conditions to observe the behavior and breakdown of cable insulation. This research may have applications for the fire protection community and, in particular, the field of fire investigation. The data collected during testing indicates that electrical cables must be exposed to minimum heating conditions before a fault will occur, aiding in the analysis of the electrical system and tracing the progression of a fire.