I once built an elevated clubhouse in my backyard with nothing more than scraps of wood found around the neighborhood. It had electricity too, courtesy of an extension cord run from the house, and an old light socket and bulb I found, which hung from the ceiling by a nail.
Try to get away with doing that today. You’d have the city inspector down on you so fast your head would spin.
I wired all the boys houses for two blocks so that we could have our own private telephones. I climbed the trees and ran the wires across the street repeatedly, it was a pretty impressive communications system and the entire time we did stuff like that, it seemed like the grownups were totally oblivious to our sub world of projects and activities.