Note: Shown as earthing through its mountings i.e. a single wire to the bulb holder on RHD and Mk1 LHD schematics but a wired earth on North American Mk2-on schematics.

Single wire to the bulb holder on these two pictures of a 1964 LHD from Bob Gibbons:

Nevertheless this replacement UK harness has a wired earth Terry Cooper

It also has spades on the wires that go to the switch - as does Bob Gibbons' switch above - but the suppliers I have checked all show switches with screw terminals, as in this example from Motaclan/Leacy: