Wiring a switch for a light fixture

[Dom]

I have discovered that there are two ways to wire a switch for a light fixture.

1) pull two NM wires to the switch - one power the other goes to light fixture 2) pull one NM wire to the switch - two wires to the fixture , one from the switch (mark the white lead with black marker at the ends) and one from power source.

My question would be which one is more preferable? I would like to avoid fishing two wires to the switch box. Any advice is welcomed. I'm in Ontario.

Thanks

Dom

[Doug Miller]

Then clearly the second option is the more preferable. :-)

It really doesn't make much of a difference, unless you might at some time want to install a device, such as a timer switch or combination switch/outlet, which needs a neutral, in which case you need at least three conductors (constant hot, switched hot, and neutral). That could be achieved either with two 2-wire cables or one 3-wire cable.

[Mark Lloyd]

I would find 1) to be preferable. It allows for any future devices that require a neutral.

[peter]

Are both methods allowed by electrical code? All switches I have seen are wires using method 1.

[Mark Lloyd]

I've seen a lot that used #2, but almost never marked as they should be. I still prefer #1, which is more flexible.

[Chris Lewis]

According to peter :

Both methods are permitted. I've seen several DIY sources expressing a strong preference for (2), which makes little sense to me at all. I think they're just copying what they see electricians doing tract houses do. It's a bit faster, so it lets them do more jobs.

Method (2) may originally have been a carryover from knob & tube days, where the hot wire tends to route between ceiling fixtures with the outlets and switches tapped off it, and where there was less concern about multiple circuits (ganged switches on different circuits) being in the same box.

I _prefer_, and almost exclusively do method (1), but sometimes (2) works out better with a reno.

I don't like marking wires either ;-)