In article , Charlie Self wrote:
IIRC, BX cable used to not have a neutral.

Of course it did.

Two wires.

Right, one hot and one neutral.

Some may have,
but I never saw it. A friend once told me that knob and tube wiring
was the safest ever, even though it never ran a neutral.

*All* circuits have a neutral, regardless of wiring method. In North America,
anyway. The UK has some sort of unusual setup that I don't pretend to
understand.

I dunno, but
I worked with it once and it's an eerie experience in some ways.

You appear to be confusing neutral with ground.