It sounds like someone added it for radio freq clean-up caused by the ignition system.
Doesn't look like an add-on, the wire is in factory wrap. But, that does make sense except for that it appears to be the only black wire going into the wrap and coming out on the oil sensor. Guess I will scrape the insulation off and see if I can find some continuity. Also...either the oil sensor is bad or my oil gauge is bad (autometer add-on) as it does not register. Electric, no tube.
