Yes — if you're running AC mains power (like 120V or 240V) into a metal enclosure, grounding is absolutely required. This is a basic safety rule that helps protect against electric shock and potential fire hazards if a short circuit occurs. 148 (Grounding Conductor): Requires metallic junction boxes—and by extension, cabinet doors—to bond to ground using a designated grounding screw or clip. 26 (Clearance. Today, we're diving deep into the world of distribution box grounding, breaking down the standards, and shining a light on those sneaky mistakes that even experienced electricians sometimes make. Whether you're a seasoned pro or just starting out, this comprehensive guide will give you practical. Metal electrical boxes must be grounded because they are conductive components that enclose energized wires and connections. Do not hide them behind walls or ceilings. Follow special rules for wet or dangerous places.