You may have a significant-to-serious safety issue there... either a
misconfigured transformer at the street (sending too high a voltage to
the house) or an "open neutral" somewhere. I'd recommend checking
other outlets for voltage... if the voltages are high, or (especially)
if they go *up* if you turn on heavy loads elsewhere in the hours, get
a competent electrician and/or the power company on the issue, stat.



He didn't say anything about fluctuations. 123V is a little high, but not
unusual. One place I lived the voltage was regularly around 124V. I wouldn't
worry about it unless it was changing significantly, not balanced between
phases, or going outside the 115-125V range.