Just want to point out that the OP is from Canada where they have 240 nm cables--- Black and Red w/ ground. This does not change what you are saying and I only mentioned it so others will know that the cabling in Canada is different. I wish they would do that here in the USA.Not necessarily. All cables are made either black-white, or black-white-red. That reflects how the cables are manufactured, it provides no indication whatsoever of the actual function of those wires. Code requires very minimal markings, but those are usually ignored, and in any case only inform people with basic skills in place. So one of those "complications" is recognizing a mis-marked switch loop.