One practical use of large switches and indicator lamps is to make a power distribution panel which can be useful when you want to control and monitor the power consumption of numerous devices such as your electronics work bench or amateur radio station. Old-school in appearance and using military surplus electronics, this power distribution panel allows for control of outlet on back. Did I mention I built it when I was 16?
Building it was easy, 120 VAC line enters through a main breaker. It is fed through an AC amp meter (with built-in shunt) then to a line filter. From the line filter it goes to a line voltage meter and filament transformer to power the indicator lamps. This AC line is then bussed out to the circuit breakers. Each breaker controls one outlet on the rear panel. As devices are switched on or off the current draw can be measured. This is well demonstrated in the video overview found after the break.
Be creative. Use military surplus switches, indicators, and other unique looking hardware. Customize to give your preferred mad scientist look while also providing valuable functionality.
Multiply the measured current by voltage to compute wattage. Keep an eye on the line voltage.
I’ve found this distribution panel to be very useful when you are living out of rental apartments or houses and your laboratory setup must be moved on occasion.