I can ask if they've noticed bulb problems. I've been over there many
times in the evening and the lighting was steady.

I know a retired lineman who runs marathons. Today at the track I
managed to keep up with him long enough to inquire. He said,
"Whole-house surge protector."

He's right in that I have one and they don't. What I observed was rapid
dimming of bulbs in a fixture as if it were repeatedly being switched
off. I suppose spikes could have scrambled the TV, answering machine,
and microwave, but the computer was plugged into a brand-name surge
protector. Does his guess sound good?

I don't understand the benefits and limitations of the surge protector
in my breaker box. It's a semiconductor clamping device that I
installed about 1985. At New Years of 1999, ice brought down
high-voltage lines a few miles away. In spite of my surge protector, my
TV and stereo were damaged so badly that they weren't worth fixing. (A
plug-in protector prevented damage to my computer, which was on.)

w_tom wrote:

Maybe loose splice on neutral wire? But this would also
cause some lamps to sometimes glow brighter and some
incandescent bulbs to fail faster. Defective neutral is also
just another human safety reason why the earthing ground rod
is important attached to breaker box.

Symptoms are getting squishy. Once it appears contained, it
squeezes out somewhere else.

Choreboy wrote:
Oh no, 240! The affected outlets represent both sides of the
transformer! There goes my speculation of a loose splice on a secondary
line. I don't know why so much in two houses had to be reset but
everything at my house was fine.

(It's been years since I looked inside a breaker box. That's why at
first it seemed natural to me that all the switches on one side would
come from the same side of the 240-V supply.)