Electrical cables contacting each other

[Scott Lynch]

.......

[Brian E Kelly]

What are the cables in question? Power and control wiring ?

[Jerry Peck]

That's called "bundling" and causes those to need to be derated. 4-6 conductors are to be derated to 80%, which would still be on a 15 amp breaker.

Not that I like it, but with just those two there, I would write it up, but not make a big deal about it. It will likely not affect the furnace, and the attic light will be nowhere near rated amperage for that circuit, so derating would not affect the attic light at all.