I'm not sure whether a contractor did this, or it was the end user, but...

Years ago someone brought in a turntable that wasn't performing properly. Someone had extended the signal wires.

I found that they had cut the two shielded cables and the ground wire to the same length, stripped all five conductors back about an inch, twisted those wires around a single 14 gauge THNN, and soldered them. About four feet away at the other end of the THNN they did the same thing.

They didn't understand why their wire extension didn't work.

This really happened -- I don't have the kind of imagination that would think of that.