Scuba Dave (Poster #30) Thank you for posting the link for All the various boxes. It's obvious that low voltage boxes have less stringent requirements in terms of enclosure (to protect against arcing/sparking) than standard voltage. That is why they're marked "Low Voltage". As I said in another post that I believe that is the main reason grounding requirements have been changed in the past few years. Because (it really started that way) PVC and other non-metallic materials are becoming more standardized for use in water supply and drainage. Adding to that is the fact that plastic (electric) boxes have practically replaced metal boxes in both Standard and low voltage. (No matter what)Don't Drink and Drive, Ever!!!