Bad connections are the most common cause I have found.
Though very non-typical, look also at the distance you may be from the transformer, My house was similar to ghosts except there were 5 total homes and mine was over 500' from the 25KVA (pole pig) transformer. Giving the power company credit, I could not tell when anyone else turned on a large load, but my own large loads were very noticable. I could show them on paper why the arge voltage drop during motor startup, but because they did not want to own up to the problem at the time, they tried to show me with an averaging recording meter that things were OK and that my delivered average voltage was 127 VAC on both lines. I am now on a new line and transformer within 200' and no complaints.