"bryanska" wrote:
They save a bundle by not having to lube the wires, but after a decade or so they start to squeal and you're stuck with having to replace all the wires. Sorry to be the bearer of bad news.

The wires are Lucas branded: "Made in the UK" and then stamped with the
phrase "Bob's Your Uncle".

Should I be concerned?

Yeah, if this is supposed to be a lighting circuit, you're totally screwed.
Lucas wires are only intended for use in darkness circuits.

Of course, that may be the root of the problem -- the oil may be ectoplasm
leaking out of a darkness circuit. A whole-house exorcism may be in order.