u/trembling_leaf_267

Newbie here, 1970's house, I need to fish out this cable to get it out of a joist I need to replace. I thought I'd just replace the old outlet with a new lever edge version, but what's this?

There's a four wire cable, red-black-white-bare, leading, maybe, back to the breaker (the house wiring is pretty unpredictable). There are three conductors, white-black-bare, leading to the next outlet. They might have a cable housing, or maybe not, I can't tell from what I see.

The tab is intact, any guesses as to what that red wire is doing? And do I need to pop out those uncabled wires and get them wrapped all the way into the enclosure?

TIA