redbrickhat wrote:
I live in an old building (1920s) in New York City.


I recently opened up 2 electrical outlets that had been covered up for
at least 30 years. Behind the outlets were 2 wires covered in cloth
braid. At first I thought this type of cabling might be K&T, but a
voltage test showed that the box was grounded, so I guess the wiring is
metal conduit or armored cable.


What is the composition of the cloth braid of these old cables? The
cloth braid looked and felt like cotton, but could it have been
asbestos or another substance?

Fray out some of the cloth. Hold a match or lighter under it. If it
just burns to ash, it's probably cotton. If it burns and melts to a
gooey mess, it's probably plastic. If it melts to a little glob, it's
probably fiberglass. If it gets orange or white hot without melting,
it's probably asbestos.
--
John