Headlight switch has facility to put a bulb in it to illuminate the switch when light switch in on in any position, but cant for the life of me see what one!!!
Have looked at ETKA and can see a bulb part number (same as fog light) but this won't fit in/work ( not big enough, it will just rattle around ) without some sort of holder.
It was fitted to other VW's that used the same switch. It doesn't come on when the lights are on, it is illuminated while the ignition is on so you can find the switch if you enter a tunnel.
Look on ETKA for Golf circa 1982.
1982 Camper 1970 1500 Beetle Various Skoda's, Ariel Arrow