I am building my own workshop and am in the wiring phase. I have four lighting circuits running through a common conduit to two side-by-side metal 2-gang boxes on the wall where the switches will be. Three of the switches are 3-ways and one is a single pole. The layout of the wiring is such that these boxes are at the end of the run – no wiring will be continuing out the other side.
My question is this: can I share a single green ground conductor for these switches to reduce conduit fill (and posibly save a little wire) or does each circuit need it own? I expect the answer will fall into one of these categories: heck no, yes but…, yep do it all the time.