Boxes installed in walls or ceilings must be flush with the finished surface to allow proper cover installation and prevent fire spread. Choose the right box based on environment (indoor/outdoor), load capacity, and durability. Check for proper IP/NEMA ratings and material quality. The NEC requirements related to flush-mounted boxes can be. A distribution box is more than just a plastic or metal housing; it is a protective enclosure that keeps miniature circuit breakers (MCBs), residual current devices (RCDs), and other switchgear organized and secure. Beyond hiding cable clutter, it provides insulation against electrical arcs and. According to Article 314.