I bought a fixer-upper house and have a renter living in it. Got a call last week, he said around 10pm all the lights flickered, bulbs popped, and circuit breakers tripped.  I went over the next morning and we turned on one breaker, current flickers, and a light bulb popped. I suspected somehow the 120V circuits were getting 220.

Called an electrician and the problem was just that one of the wires coming out of the meter box had a bad connection.  So I learned a bad connection can do more than just cut power, it can do all kinds of weird things.