2 circuirts using 3 wire romex?
For whatever reason, the electrician involved in a recent kitchen remod used 3 wire+ground romex to wire from a wall switch to ceiling lights (we never specified two switches-have no idea how we ended up with 3 wire.) Later my wife decides she wants a ceiling fan in the kitchen. While trying to figure out how to get power into the attic to run the fan, I discover the 3 wire cable and notice that the red wire is totally unused, capped at both ends with a wire nut, one end in the wall switch box and one in a junction box in the attic. Can I use this extra wire as a separate feed, using the white wire in the cable as a common neutral? I would connect (pigtailing the switch) the red wire to black wire before the switch in the switch box and then run a regular 2 wire+ground romex cable from the aforementioned junction box in the attic to the box for the fan. The fan and the ceiling lights would share the white neutral in 3 wire cable. Total load would be 600 watts. This will obviously get power to the fan with minimum effort on my part, but is it code approved? Snaking an additional 2 wire romex cable down the walls of old houses is not real easy (I tried) and discovering the spare red wire was a godsend.