The outlets that got replaced already seem to have new wire runs as
well. These outlets are connected to beige flat cables (I think this
is called Romex). The older/original wiring is going to metal boxes.
This cable looks to be a rubbery substance covering some kind of mesh.
The cable says Citex NON METALIC COVERING. I have pulled one of the
older outlets, its in a metal box with four wires coming in (two
black/two white).