I am attaching some smoke and heat detectors to ceiling boxes. The boxes are connected by 12-3 where the red wire is for the interconnect between alarms. The 12-3 is fed off of a standard bedroom circuit.
The 12-3 also has a ground wire, of course. However, the ceiling boxes for the alarms are plastic. And, the alarms do not have screws to attach ground wires.
Where should I put the ground in each plastic box? I will pigtail feed-in and feed-out grounds in each box. Should I do more than this? And what about the ground in the final alarm box, where there is only a feed-in wire? Should I just wirenut the ground and let it sit in the plastic box?
thanks,
mh