The mystery deepens in our ungrounded house

[Wash. state Desk Jet]

9. That what I couldn't figure out -the cable-pipe . it the only other way.

50's wire that replaced the old knot and tube was 12'2 without the additional copper ground.
it wired in about the same as knot and tube except the replacement wring was wrapped in insulation.Run up the wall to location the same way. Back than all junctions box's were metal.
Metal shielding over the wire was not and is not required unless it is a commercial building.

Although the commercial wiring is the way to go. Learn something everyday !

I didn't know rom ex isn't allowed in some areas.
Is that electrical code in Chicago for residential and commercial construction ?

And what about old homes and old commercial buildings that were wried in before the code was changed?

Say a 90 year old house ?
And what about remodel in old structures where tying in new materials with old stuff happens?

Code regulations along those lines in Chicago.