As you can see there is a cable with some syrup coloured gunge or whatever on it, on close inspection it actually looks like it’s coming out of the wire. The cable itself I think goes from the fuse box(I’m guessing battery fuse) and joins to the positive battery terminal as you can see in the picture, unless I have confused it with the second cable which went underneath the engine somewhere though I mostly sure this went to the fuse box.
What is this substance and is it anything to worry about/take action with?