Yes I could have bought one for $20 or less but that's no fun.
I had all the parts already, 3x 110v panel lights (LED), GFCI from an old aircon unit, and I carried the leads through to some insulated banana plugs so I can plug straight into a meter if thing s look a bit funky. The light code works the same as the bought ones except my first green light is L-N then L-G & N-G (red) bad if that lights up . + I can see the lights from a distance when trying to find circuit breakers