Many years ago, I used to have a "stupid" charge for clients.
I was completely upfront about it, and what I called it. i would explain this to my clients as part of my rates before starting a gig, or going out on a service call...
If you make me do something really stupid and irritating, because you didn't do what you were told to do, didn't follow instructions, repeatedly made the same dumb mistake, or called me out because you did something really dumb (like unplug the machine and not notice for example)... You got the stupid charge...
Double my hourly rate, two hour minimum charge.
If said call, or call out, was after hours, on a weekend, or a holiday, you got my "special stupid" charge, FOUR times my hourly rate... Eight times if it was any two, twelve times if it was all three.
At the time I was charging $35 an hour for basic IT service, including travel time from my office to their site if more than 15 miles.
So, sure enough, holiday weekend comes around, and I get a call at 8 o'clock at night from a very wealthy client (a good sized business owner who had a serious home office that I set up, with full connectivity to his business)... Systems not working... Can't connect to the internet, can't print. And this guy has a 24/7 monthly service contract with me, with a 4 hour response (he paid for it gladly, and in general he was a very good client).
I go through an hour or so of troubleshooting, including specifically asking the guy to check all his power and interconnect cables, and look for power lights, and explaining to him my stupid charge. He was adamant he checked everything and he needed me to come out there (over an hours drive each way) right now... I explained to him that if when I got there it wasn't a covered service, he'd have to pay a minimum of six hours service (3 hours travel, 2 hour minimum service charge, one hour out of hours phone service) at the "special stupid" rate (over $2500 total)... He was absolutely certain.
So, I drive out there to the middle of nowhere mountains, walk into the office, look hard and sideways at the hardware for about 30 seconds from across the room....
...Walk over and plug the power strip the modem and router were plugged into, back into the wall.
Then I turn them both on, plug the phone line from the modem back into the wall, wait for them to come up, turn to the PC next to them, try to access the net and dial out, hear the modem dial out, and watch the browser start loading a page, and the printer start printing a test page.
I turned around again, and the guy was already standing there with a signed check in his hand.
From greeting him at the front door, to that moment, I hadn't said a word... I started to say "that's not necessary" (in fact I wasn't going to charge him the stupid charge at all, just the 6 hours).
He interrupted me, handed me the check and said "Here's $5000... never speak of this to anyone".
... And I didn't, until after he passed on a few years later...