What to do with ground wires(3-wire house wiring)?

So you are using NMD 14-2 solid core house wire? That’s pretty nasty stuff to make connections with for most low voltage train stuff, but hey, whatever. You are referring to the bare third ground wire I gather, that normally connects to electrical box ground screws right? If you don’t need them and will never use them, sure, just trim them off.

Rod

If you are only using it as low voltage 2-wire then, yes, you can clip the bare wire off. I don't see how removing that one bare conductor will make any difference space wise.

NM wire (romex) wouldn't have been my first, second, or last choice....and I've got lot's of it around (retired master electrician).

But your railroad, your rules.

Thanks Rod....Yeah, some heavier guage wire for the spokes and smaller guage up to the track.

@RSJB18 I dont use bus wiring. I use hub and spoke and I radiate outware to each block. I have six blocks so at the hub I'm getting crowded so when I cut them all off on the hub end I get some space. Thanks for your input.