I've run across some of this green slime in the mains flexes of some 1960s/70s radios I have.
It's a sticky kind of goo and you always see some of it oozing around the pins of the
molded-on plugs.
On one particular radio, it was so disgusting I chopped the molded plug off and screwed on a replacement cap. I probably should change the entire flex though.
