Let me tell you a story about my landlord's girlfriend.
The Apartment I live in is a duplex... a studio built into the side of an old house... My current landlord and his girlfriend have lived in the main house for about 3 or so years now, since buying it from my prior landlord. in that span of time, Linda has caused a few problems, and is still doing so. I have my computer and AC on one breaker at the house, which is also connected to the bathroom in the main house. *every* (and I mean *every*) two to three weeks, she forgets, and uses the hair dryer in the guest bathroom, killing my air conditioning, and snuffing my computer... actually drained my UPS to the point of needing a replacement. I've told her, and David has told her each time that's she can't, but her selfish, beer-addled brain seems unable to retain the knowledge. Since I can't move the computer or air conditioner... this is really the only alternative. I'm going to ask David tonight if he can disable the plug in the bathroom.
Time for some pavlovian therapy. I think if she receive a mild electric shock every time she was inconsiderate, hmm... no, that wouldn't work... she's be electrocuted from the stacking.