On a 20A branch circuit, does the NEC permit 14ga wire to be used for the switch loop of a fixed light fixture?
Before anyone gets unhinged - I'm not trying to save a few cents on wire, the question just came up and I *think* I recall being taught "yes" - but that was 30-odd years ago, by an old-timer who'd been sparking for 40 years at that point -- so it could be I'm misremembering, or that it was compliant when dinosaurs walked the earth, but isn't today.
This is a persistent Notion from the Urban Legend Electrical Code book. Bear in mind that the switch leg carries the entire current of the circuit. While this would be ok with only one light bulb, what would happen if the load exceeded this or during a fault condition it is possible that the 14ga wire would burn before the 20a breaker would clear the line.