I know it would be nice to give her a real switch, but my wife, with the same problem, simply asked me to make her a short wooden pole to activate both the fan switch and the crank to open the vent. I used a 1/2" wooden dowel 18" long, put a round disc with 4 short "fingers" on one end to allow her to turn the vent crank, and drilled the other end for a wooden cross "tee", which acts as a handle. We keep it beside the toilet, and it works great for her. Also a lot simpler and cheaper than messing with wiring and placement of a switch. Just a thought.
2003 Ford F-350 V-10 Crew Cab 4WD Long Bed
2004 Jayco Designer Medallion 29 RLTS 5th wheel
Bill, Gayle, and Mindi (dachshund)
Retired at last !
Nothing is foolproof to a sufficiently talented fool.