Various means were used by the electric companies to lock their magneto switches. Some of them will be shown.
Lighting Switches
For the most part, separate lockable lighting switches appear to have been uncommon. The only ones that we are aware of are aftermarket switches for use when a driver had installed an aftermarket lighting system.
Magneto and Lighting Combined
Combination magneto and lighting switches seem to have been the rule for more than a decade, probably beginning in the mid teens. Manufacturers varied the interoperability of the switches, often using a lot of imagination.
Locking Magneto Switches for Antique Cars
The Technical Side of Locking Magneto and Lighting Switches