When I worked for the power company I experienced another weirdness. In one particular office building, every computer, after 6 months or so, started rebooting itself or simply turning itself off. It didn't matter how old the computer was. In other words, bring in a computer that had been working for 3 years, give it six months, and it will start rebooting. Buy a brand new computer, plug it in, and wait six months. Turns out that the building was slightly overvoltaged (130V), and was burning out PSU's over time. It wasn't enough for the UPS's to kick in, but enough to damage the PC's over time.

Luckily, since I was working for the POWER company, it was easily remedied.