When installing a box in a combustible wall, what is required for the front edge of the box?

When installing an electrical box in a combustible wall, the requirement for the front edge of the box to be flush with the finished surface is critical for safety and functionality. This position ensures that the box is properly mounted and reduces the risk of fire hazards associated with combustible materials. If the box were recessed or protruding, it could create complications for wiring connections, potential exposure of the box to damage, and issues with securing the cover plate. Such misalignments could lead to unsafe electrical practices, including potential arcing or short circuits, which could ignite nearby combustible materials. Ensuring that the box is flush with the finished surface also helps maintain the integrity of the wall installation and provides a professional appearance.