Coober Pedy's a long standing still active mining "cave" town - and there are others about the globe, some going back a thousand years and more.
There was a chap from that family background (he was born in the UK perhaps but his father wasn't) who rennovated an Ye old Englishe cave dwelling ...
https://www.granddesignsmagazine.com/grand-designs-houses/th...
There are channels carved out in the rock for cabling and wood fire chimmneys, etc.
Also bookable for retreats: https://www.therockhouseretreat.co.uk/
There are a good number of caves (eg: one former tourist cave on a property I once owned in the WA S'West Karri forrest) that have solution pipes that go straight down from the surface into the roofs of various chambers - they're good for running cable.
Circling back to mining, underground mines can be vast systems of tunnels with custom trucks and trains running about in addition to borehole machines and other stuff - Mining Comms is a whole field with hybrid cable + transmitter (with repeater) hubs, etc.
Not saying this is cheap or easy, but it's all doable - and for the DIY home handy type it can cost time and effort rather than money if they have access to mining auctions | closing down | old stock etc.
Good acoustics and laying utilities in and out is a handy skill for farms, concerts, and apocolyptic bunker builing.