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."