This here is nightmare wire. It is some knob and tube with thermoplastic-sheathed cable
(TPS) spliced in. What they were trying to do was have a switched outlet. The light in this room didn't have a box. Rather than take the time to do this right, put in a box, and make the connect there, they simply stripped the cloth covered knob-and-tube wire and wrapped in the TPS. The knob-and-tube wire is steel and the TPS copper. Generally one should avoid connecting metals of different types due to differing expansion rates. The connection could loosen over time, increasing resistance and causing a fire hazard. In addition, junctions should always be in a box. There is nothing legitimate about this splice and I'm glad it is no longer connected.
At some point, I will have to fix that outlet. I should be able to use the existing wire to pull new wire to the box, and then I can connect that wire to a power source. For now that outlet is disconnected.