voltage fluctuations?
 

I've been noticing what I'm guessing is the result of some kind of
voltage fluctuation. At first the only symptom of this was when I was
driving highway speeds at night the lights (headlight and dashboard)
would kind of flare up a little brighter intermittently. More
recently I noticed the AC fan doing the same thing. I only noticed
that while parked with the fan on high.

Anyone have experience with this before? Ideas?

the car is a 98 Civic LX AT with only 53,000 miles.

Thanks.