We are in an old house.

There were old remnants of knob and tube in the basement - a few knobs were still on the floor joists, but most everything appears to be 1950s era 12-2 cable without ground. The 1950s seems logical as that's when my great-grandmother bought the place. It was probably re-wired before it was sold, or she had it done shortly thereafter.

This 1950s era wiring appears to be in good shape. Good covering, good insulation, etc.

The problem is that there was a flood in 1977 and the house got "renovated." Ha. As near as I can tell, every new grounded outlet has 12-2 w/ground Romex attached to it . . . except it is spliced into the old stuff that has no ground.

As if that's not bad enough, I've yet to find one of these splices that is inside a box. The 5 I've uncovered in the past week have all been twisted wires covered in electrical tape. (And not covered well.) And they are just hanging out in walls and floor joists.

I pushed aside some insulation in the basement in order to add a new circuit the other day and found such a splice. With bare copper peaking out from under electrical tape.

What are the requirements when I find junk like this?
Was it ever legal / right to splice things like this?
I'm guessing it's not legal to have a grounded outlet spliced into wires without ground?
Am I required to track it all down and rip it out? Certainly I am taking care of the ones I find, but ...

Thanks,
Jim

Open splices of K&T are the way things are done but they should always be in free air not. Junctions of about any other conductors require boxes (or some other listed way of doing it). Grounded receptacles need to be grounded or protected by GFCI.