I've told this story before, but will re-tell it one more time for kicks. My old Bigfoot
motorhome had a toggle switch like that in the back bedroom. On one of our first trips in it while staying at a nice woodsy campground in Michigan, I got it into my head to solve the mystery of what the switch was for and flipped it over and over and over for a long time and didn't notice a thing in the motorhome changing.
The next morning, our neighbor at the next site over (very politely) let me know that the repeated flashing of the extremely bright outside floodlights on the side of our Bigfoot
had made it difficult for him to fall
asleep. He was kind enough to actually laugh about it when I apologized profusely and explained why the lights
were flashing. Mystery solved!