If you live in the US and your house was built in the past 20 years or so, check if you have old school phone jacks around. Many contractors took a “short cut” and ran dedicated cat5 cable to each of those wall ports instead of daisy chaining cat3 (probably was cheaper to buy cat5 in bulk).
Take the face plate off your phone jack and if you see a wire with four pairs of wires inside, only two connected to the jack, you may be in luck. I had rented a few townhomes which were like that, enabling me to build out a simple wired network without modifying or drilling at all.
Can confirm, this was the exact situation in my 2004-built townhome. Everything came into my bedroom closet. Learned how to terminate Ethernet, stuck a switch in there, and had a great home net.
Yeah, I've already cut all the phone lines since there was a tonne of noise when I was with ADSL. I've now got fibre into a closet which is connected straight to a modem and switch... I'll be getting an electrician to CAT6 from the switch the the rest of the house and then AP from the terminals
Take the face plate off your phone jack and if you see a wire with four pairs of wires inside, only two connected to the jack, you may be in luck. I had rented a few townhomes which were like that, enabling me to build out a simple wired network without modifying or drilling at all.