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wiring at the switch wiring at the bulb

As can be seen by the first image( switch wiring ) , 4 black wires are connected to 1 terminal, and 3 red wires are connected to the other terminal , there is also a unconnected copper wire ( I am assuming that this is the earth )

the light was working until recently and now even after changing to several working bulbs it does not work , i have checked at the bulb using a voltage probe that its not getting any voltage.

I have a couple of questions

  1. the switch should switch the live line right ? , so there is no neutral at the switch ?

  2. why would someone connect multiple live wires at the switch, this would mean that the switch connected more than one bulb/appliance ? , but it only used to switch one light in the room

    1. given that there is a minor hole ( visible in the picture )in the black cable ( assuming its the live wire), is it possible that it shorted with the earth ? , i have checked the breakers but they seem fine but noticed that the breakers are really really old wire fuse type ones.

    2. is it possible that the switch is fried ? , since there is power at the switch but not at the light ?

BTW i am located in Brisbane, Australia

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    The only other time I recall seeing a hole in wire insulation like that a #10 cable for a clothes drier arced through to the metal strain relief clamp with a rather violent pop. I can't explain the 5 wires on your switch, but that looks a bit dangerous. Once you figure it all out, I'd clip off the ends and start fresh with good connections.
    – isherwood
    Commented May 24, 2017 at 2:25
  • Is it possible this is low voltage wiring? Au's mains voltage colors are same as everyone's low voltage colors.
    – Harper - Reinstate Monica
    Commented May 24, 2017 at 14:08
  • @Harper: Ozzian wiring colours are the same as old UK colours. Of course, electrical power distribution engineers do consider 240 VAC to be "low voltage" - so you can be right too :-) I've only ever seen those BC/B22 bayonet sockets (bulb holders) used for 240 VAC though.
    – RedGrittyBrick
    Commented May 24, 2017 at 15:37
  • @RedGrittyBrick what I mean is everyone in the world uses red=+ black=- for 6V and 12V DC wiring. Hence in the States if you see red and black going to a low wattage load like a luminare, that is surely 12V because the only other thing those colors would be is 240V, and who would run 240V to a luminaire? ;-)
    – Harper - Reinstate Monica
    Commented May 24, 2017 at 15:49

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This needs to be looked at by an Electrician as it looks like Vulcanized Rubber wiring (VIR).

This is a Fire Hazard !!!

Your house wiring insulation may be the cause of the light not working.

Vulcanized Rubber is what they used before the 60's to insulate house wiring and overtime it can become brittle and break off leaving the wiring without insulation.

dangerous old wiring- "Avoiding the perils of age"

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