A trick I used for "fishing a wire" in our stick house was to get a length of Romex-type house wiring, solder a small flaslight bulb across one end and a flashlight battery across the other. I added a length of string to the lighted end.
With about 1/2" diameter holes at each end of the proposed run for the wiring, I then pushed the stiff house wire, with the light on, down the wall while DW looked for the light to show at the other hole.
When the light appeared, I was able to snag the string and pull it through and use the string to guide the wiring I wanted to install into position, then removed the piece of Romex.
Frank and Eileen
No longer RVers or FR owners