Like many others here, I am looking to replace a 3-way switch with a "smart switch" that requires neutral. As I inspect my wiring (home built in 2009) I note that I can't tell the difference between two wiring schematics by looking at the switches themselves.
In looking up diagrams of these to add to this post, neither of these arrangements seems very common. I would add pictures of my switch boxes but they're both multi-switch boxes, one of which is very full and hard to track in-person, I can only imagine it'd be more confusing from photos. The other is extremely simple, 14/3 connected straightforwardly. I narrowed down my situation to 2 possibilities based on what I see.
Can a voltmeter or non-contact voltage tester help determine which of these I have? Or is there another way to tell without opening up the lights themselves? I found diagrams with 2 lights but I actually have 4 connected somehow to these 2 3-way switches.
EDIT: Adding photos of switch wiring.
Switch 2, which I found straightforward:
And here are two of Switch 1 which looked straightforward at first, but eventually I saw the black wire from the 14/3 does NOT go directly to the switch, it's coming from the 14/2 I marked in green (mspaint). I lose track of the black from 14/3 and the white from 14/2 as they go off to the left side of the box. Short of stretching all the nutted wire bundles out of the box, I'm convinced they're connected to each other (unless that doesn't make sense). I don't know that I can get all the wire bundles crammed back in the box as neatly as they are now so I've tried not to move them so far.