Not to long ago folks were sharing what they were doing to discourage theft. One thing was a on/off switch in the line for the Jack power.
I decided that was worth looking at but just now got around to it(read remembered).
I got under the frame at the tongue to see if there was a good place for a switch there and discovered an in-line fuse in the jack power line just in front of the 7-pin junction box.
I removed it and now I got an on/off 'switch'. Very easy to get to. Don't have to get under trailer now that I know where it is, just reach under the tongue frame and pop it in/out. KISS!
"There's a woman for every man". If true, some rascal has two!