24 ga paralleled is the same as 21 ga, so that's about 13 ohm/1000ft. If that run is 20' (up and back down again), that wire presents a resistance of 0.26 ohms. If that's a 240VA 120V load that's 2A of current in the wire, power lost in the wire is P=I^2*R, or about 1W. Despite how bad the installation is, that wire wouldn't even get warm. I still don't approve, and I'm sure this much thought didn't go into this installation.
