This mid-stripping of insulation is a fairly common practice. Instead of pigtailing the hot wire to another device, it is midstripped for attachment to the first device and the same hot wire continues on to the second device. All your son has to do is cut the midstripped wire and pigtail that cut wire to both the new 3 way switch and to the other end of the wire it was cut from. The white wire may not even be present at all if the source is not at the switch. To remove the back stab the easiest way is to just cut it. You haven't mentioned a second traveller. Do you see one?

Im not sure if he saw another traveler. However, is it a bad idea, instead of cutting the mid stripping and make a pigtail, just remove the screw and place back on new outlet the same way? Would save the trip for more wire, a wirenut and doing something unfamilar.

Sorry for second post, I told my son but he asked....

For the wire nut method on the midstripped wire that would mean there was 3 wires under the nut, one of which going to the switch.

He wasnt sure about the 2nd traveler, and said he didnt see white wire in box so he now assumes the neutral is in the other switch box.

Again though, is it alright to just swap it out with the midstripped wire or is that going to be hard?

Mum -

If the existing 3 way has a black screw, that is the hot from the source, fyi.

I'd say your idea of just swapping out the old and putting in the new with the same mid-stripping method is fine. If this setup worked before and now there is just some mechanical issue with the switch, your idea is primo.

Tell your son not to swap out the switch without flippin' the breaker first, no need to give himself a 120 volt hair curl. ;)

Just curious, why does the switch need replacing? Most 3-way switches have a common attached to the bronze screw and two travelers. Am I missing something?

I hope you dont think im nuts, but I think maybe it needs replacement because for a long time I noticed sometimes when you flip the switch (which controls a flourescent 40w x 2 fixture) I heard a very soft hum for a split second. Not a buzz or crackling though and the light works fine. Its barely audible but I notice it, my son does not.

I thought it was just the fixture/ballast warming up but when you use the other switch in the 3 way setup it doesnt occur at all. Should I be concerned?

I think you are hearing the ballast warm up. There are different types of ballasts on similar light fixtures. A switch does not need to be replaced unless it stops turning the light on due to internal shorting or mechanical failure. If your flourescent light starts behaving funny or making unusual noise it probably needs a ballast replacement. For cheap fixtures, just get a whole new fixture.

Mums,

I think your switch is fine, just turn up the radio.

It hums because it does not know the words. It also may be that the switch where the humming is evident is the one closer to the fixture.