www.LMC.com
The library
You can find wiring diagrams for free online thru your public library. You will have to get a library card so you will have a number to logon to the site then research database.
google imagesGo to this web site: http://www.vintagebus.com/wiring/index.htmlIt has wiring diagrams for Bus, Beetle, Super Beetle, Karmann Ghia, Type 3, Type 4, Type 181 (Thing), Type 48 and Kubelwagen. Years ranging from 1950 - 1991.
The Cisco Kid - 1950 Big Switch - 1.4 was released on: USA: 26 September 1950
The Cisco Kid - 1950 Big Switch 1-4 was released on: USA: 26 September 1950
The Gene Autry Show - 1950 The Double Switch 1-6 was released on: USA: 27 August 1950
The Web - 1950 A Switch in Time 1-47 was released on: USA: 23 May 1951
check your local library or you can order the repair manual.
look on top of the brake pedal or on the master cylinder.
If it's not on top of the brake pedal look on the brake reservoir.
It was first invented by Joseph Conrad Barrette who worked for GE in the 1950's. Unfortunately, he did not patent his idea and it was stolen by GE.