msmith1199 wrote:
I came home once on a nice sunny day to find my generator running on the motorhome on the side of the house.  My generator (and probably yours too) had a switch on the generator itself facing the top.  I found foot prints from a cat on the generator as well as a clean spot on top where the cat had been sleeping.  He somehow managed to step on the switch and start the thing up.  It's never happened again so I assume he scarred himself a little and never came back.
I doubt the cat would weigh enough to turn it on. That switch has to have some pressure to turn it on. I do not think a cat could do it. 
I believe that what other posters here have said about the plug that gets moisture makes more sense, but Onan will not admit that there is a problem. I have read hundreds of reports of generators starting without having an auto start, and that raises a red flag. But these big companies are all alike and will not put out a recall until something serious happens.