years ago I installed a outside outlet then found my neighbor would
plug in our house outlet rather than drop a extension cord thru his
window.

So I added a master off switch inside our kitchen.

One day my neighbor knocked on the door, and asked my grandma to turn
on the power. she said sorry I dont know where the switch is, while
she stood right next to it...

That swich has been very useful for stuff like christmas lights.

I didnt mind the few pennies of power he was using, it was the
principle of the thing...