I want some information on type af wire. Is it safe to leave in place inside of a fixture, and is it safe to use a cord made of af wire, or will it shed asbestos fibers? I expect that you shouldn’t cut or strip insulation on af wire, I just want to know how you deal with it if you ever come across it.

As long as there isn't risk of a short circuit from deteriorating insulation, I'd leave it as-is.

Same as drilling thru the old slat asbestos siding to mount a new service. Been there for years but when you drill it with a hole saw, well.

Does it start to crumble?

Before messing about with asbestos make it wet this will prevent the fibres from getting air born....better still renew the wiring and dispose of the old stuff carefully. Some war time radios sold in UK from America used a cord which was resistive covered with asbestos to prevent fires, this enabled to run these radios on 240v rather then using a transformer.

Hello,
As long as there is no movement, no electrical issue and no working on it it can be kept in place. Any moovment will cause fibre to get of and in the air. Therefor it should be handled on ly in Wetend state.

Best Regards,

Alex