"free electricity" means IMO "stealing electricity"
Instead of stealing electricity to maximize mining profit to be able to afford a nice car, I´d recommend just to steal a nice car(*). Thats more straightforward.
(*) stealing is illegal, don´t do it
It's a lot easier to steal electricity because someone forgot to meter it properly then it is to steal a car because someone forgot about it.
Also, in some places you can get free power at night, off peak. You can also install solar panels. Are people who use solar stealing sunlight?
I have free electricity but if I started running an avalon or something I'm sure questions would be asked and some part of my contract would be pointed out to me. There's no such thing as completely free electricity just like there is no such thing as unlimited web hosting.
Actually, there's a good chance your apartment doesn't even have it's own meter. They might see an extra $50 a month in their power bill, but they won't know where it's coming from.