First of all, I'm only a DIYer, and second I'm not a qualified electrician.
And I certainly have no familiraity with Canadian systems.
However, it seems to me that you have a typical three plate system.
Check out this site for the three plate wiring diagram:
http://claydons.org/public-html/elec/domestic_electrical_wiring.htm
Hopefully you'll see that there is no need for a neutral at the switch.
There is a live/hot wire to each light but this is not connected to the light directly. It is only there to connect to another wire to deliver a live/hot wire to the switch.
At the switch is that live/hot wire and a switch wire which provides a live/hot wire to the light only when the switch is operated. There may also be an earth wire at the switch.
So you probably have three live/hot wires capped together, which can stay as is, probably the red wires.
Three neutral wires capped together which you will need to connect the return from any light fitting, possibly the white wires.
And the yellow wire is the switch wire which should also be connected to the light fitting.
The green/copper wire is probably the earth and in the UK that should now be insulated.
You could test the wires with a suitable tester to verify the above.
The red wires would be permanently live, the white wires permanently not live and the yellow wire live or not, dependent on the switch.
You'll see from this site that neutral wires in Canada are white.
http://www.allaboutcircuits.com/vol_5/chpt_2/2.html