Ben,

I too shudder to think that this may once have been part of a school curriculum, but such parts were once common. Well into the '20s and possibly even later, knife switches were standard for service equipment, and cleat lampholders such as those shown here were in common use.

Even today, the NEC allows cleat lampholders with exposed live parts, if they are located a minimum of 8' above the floor! Needless to say, I would never install one.

And those single-pole knife switches? I visited a church in Mexico in 2001 that had those for lighting, in public areas, at customary wall-switch height! [Linked Image]