You folks (almost) sound like the US Congress ;-).

I appreciate all the responses. Thanks!

We're waiting on a call back from the electrician.

Meanwhile, some more detail:

I'm using an analog multitester (Radio Shack - Micronta). [And the wet
finger test, which gives a definite tingle/mild shock only between a
TV connector and antenna cable end or outlet screw.] It's a roof top
antenna, no cable or satellite. Results are the same with the antenna
grounded or ungrounded. I see no electrical connection to the antenna
or cabling, though I can't see what's in the wall.

I tested nearly all the house outlets with a GB plug-in circuit
tester, and all tested correct, hot/neutral are not reversed, no other
faults, all are 125V hot to ground, 0V neutral to ground. Only
two-prong appliances give a voltage reading, nothing off grounded
appliances. I tested the TV, VCR, DVD and mixer unconnected to each
other, and each on several different circuits.

Results, at various multitester AC voltage range settings:

MIXER:
range mixer off mixer on
250V ~30V 25V
250/2V* ~30V 25V+
50V 7V 7V
10V ~1.5V ~1.5V
[*250 divided by 2 = 125 range. Meter needle is in near identical
position on the 250V, 50V, and 10V range readings. Readings from mixer
housing, handle, other parts.]

DVD:
250V 50V
250/2V 50V
50V ~18V
10V ~4V
[Needle in identical position on 50V & 10V readings. Same readings
with DVD on or off. Readings from housing and output jacks.]

VCR:
250V 30V+
250/2V ~32V
50V ~17V
10V 4V
[Needle almost identical position on 50V & 10V readings. Same readings
with VCR on or off. Readings from F-connector and output jacks.]

TV:
off on across night light prongs
250V 75V 100V ~45V
250/2V 75V 100V ~40V
50V ~46V pegs 35V
10V pegs pegs pegs
[Readings from various TV connectors/jacks. I didn't test night light
with TV on.]

I'm sceptical of some of these readings because the needle is in the
same position. But I also don't know what that means.

We bought this 12 year old house 5 years ago, so newish wiring and
AFAIK no DIY hackers fiddling with it like in the old houses I've
owned ;-). We had an addition, with subpanel, put on 4 years ago. I've
done little wiring on this house myself, other than adding one outlet,
replacing some switches and light fixtures, and all seem okay far as I
can tell. We had DSL installed a few months ago. There's nothing else
unusual electrically, that I can tell. Lights don't blink or burn out,
all appliances and electronics work properly.

The main panel and subpanel look right to me. I have some idea what's
what as I've done some wiring before including running new circuits,
though not in this house, but since I don't understand this problem I
don't know just what to look for. I can't be sure, but I think this
started recently, when the antenna reception started flaking. But I
can't be sure since I never thought to test voltage on appliances
before :-).

I just got home from work. While we wait for the electrician I'll try
testing with appliances and circuits turned off and on.

Any other thoughts, suggestions, or other questions? Thanks!

--
Luke