I have an old house (1858) that was wired in the 30's with romex. I was
changing a light fixture. I turned the power off to the circuit removed
the old fixture and while I was wiring in the new fixture I received a
slight shock when I touch the metal box and one of the wires.
Any ideas?

I have an old house (1858) that was wired in the 30's with romex.

Describe what you're calling 'romex'. It's very unlikely what you have
there is the same thing considered 'romex' today.

I was
changing a light fixture. I turned the power off to the circuit removed
the old fixture and while I was wiring in the new fixture I received a
slight shock when I touch the metal box and one of the wires.
Any ideas?

All sorts of ideas. Most likely a miswiring of the circuit such that it's
shared with another breaker. Half the leg going to one breaker and the
other on another. Usually happens when someone tries tying in another
switch or outlet inside an already crowded wall box (or they're just plain
stupid).

Test the other breakers to see which one is set up wrong. It may lead to an
obvious solution that can be easily fixed.

-Bill Kearney

rich wrote:
I have an old house (1858) that was wired in the 30's with romex. I was
changing a light fixture. I turned the power off to the circuit removed
the old fixture and while I was wiring in the new fixture I received a
slight shock when I touch the metal box and one of the wires.
Any ideas?


If the "slight shock" was just a tingle, chances are there's just a
little capacitively coupled current from an energized conductor running
in close proximity parallel to what would otherwise be considered an
"open" lead.

Or, there could be a high resistance path created by dampness or through
years of crud film accumulating between an energized circuit and
something connected to the wiring you touched.

If the fixture job is already finished, then that's that. But it's
always wise to use a test light or voltmeter to make sure things which
are supposed to be "off" really are.

HTH,

Jeff

--
Jeffry Wisnia

(W1BSV + Brass Rat '57 EE)

"Truth exists; only falsehood has to be invented."

Jeff Wisnia wrote:
rich wrote:
I have an old house (1858) that was wired in the 30's with romex. I
was changing a light fixture. I turned the power off to the circuit
removed the old fixture and while I was wiring in the new fixture I
received a slight shock when I touch the metal box and one of the
wires. Any ideas?


If the "slight shock" was just a tingle, chances are there's just a
little capacitively coupled current from an energized conductor
running in close proximity parallel to what would otherwise be
considered an "open" lead.

I guess that could be possible, but my experience is that it would take
a very large capacitive coupling to do it.


Or, there could be a high resistance path created by dampness or
through years of crud film accumulating between an energized circuit
and something connected to the wiring you touched.

If the fixture job is already finished, then that's that. But it's
always wise to use a test light or voltmeter to make sure things which
are supposed to be "off" really are.

HTH,

Jeff

--
Joseph Meehan

Dia duit

The romex I have has 2 wires in it and the metal casing is used as a
ground.

rich wrote:
The romex I have has 2 wires in it and the metal casing is used as a
ground.

Does the metal casing consist of spiral wound interlocking metal tape?
If it does you have armored cable which is commonly called BX.
--
Tom Horne

Well we aren't no thin blue heroes and yet we aren't no blackguards to.
We're just working men and woman most remarkable like you.

In article .com, "rich" wrote:
The romex I have has 2 wires in it and the metal casing is used as a
ground.

That ain't romex. It's armored cable (BX).

--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.

"Jeff Wisnia" wrote in message
...
rich wrote:
I have an old house (1858) that was wired in the 30's with romex. I was
changing a light fixture. I turned the power off to the circuit removed
the old fixture and while I was wiring in the new fixture I received a
slight shock when I touch the metal box and one of the wires.
Any ideas?


If the "slight shock" was just a tingle, chances are there's just a
little capacitively coupled current from an energized conductor running
in close proximity parallel to what would otherwise be considered an
"open" lead.

Or, there could be a high resistance path created by dampness or through
years of crud film accumulating between an energized circuit and
something connected to the wiring you touched.


Or back feeding through a "leaking" neutral and then to ground. In other
words, there might actually have some current running through it. In sound
equipment it causes a buzz when equipment is plugged into different phases
of the breaker box and there is a current between neutrals.

If the fixture job is already finished, then that's that. But it's
always wise to use a test light or voltmeter to make sure things which
are supposed to be "off" really are.

HTH,

Jeff

--
Jeffry Wisnia

(W1BSV + Brass Rat '57 EE)

"Truth exists; only falsehood has to be invented."