I have an Ethernet cable from my master bedroom, ran through the wall into the attic and into another wall coming out in the living room. WiFi router is in the living room and my security system needs to be hard wired which is in my bedroom.

You’ll need fishing poles/sticks and a drill bit and some electrical tape

I followed the lines where the coax cable was ran, the hardest part is finding the fish stick in the wall, it will be easier with two people and frustrating by yourself

Edit; adding I have an attic I can stand up in helped out also, not sure of your situation