my grandfather was a child of the depression era, so he didn't throw out or "waste" anything. Some of his house was wired like that, random lengths wire-nutted together under the house or in the basement!
It make perfect sense. One side is ground and the other is hot!
And in the middle is smoke where it's warm!
I feel your pain, O.P.
I didn't want to, but I had to buy a new under dash harness because mine was in such poor shape.
The 70's with CB radios and 8-Tracks, really took its toll. I think they used a chainsaw to cut the wires.