Imagine back to the early 20th century. Home electrification in America was a new and somewhat frightening idea. What mixed feelings folks must have had - you could have electric lights, but you had to have wires running through your house. That stuff could catch your house on fire! But compared to kerosene lamps, it was easy to choose electricity. At least you didn't have to trim wicks and clean globes.
I remember the wiring in my grandmother's house. In the far corner of the attic there were porcelain spools on the wall. They held the fabric-covered electrical wiring that came into the house from outside. I've since learned that this is called “knob and tube wiring.”