It's actually an inverse first power law, assuming that the distance of the drone from the wire is much less than the length of the wire. The inverse square law applies only to a point source of electrical energy, to a sphere, or to an object whose largest dimension is much less than the distance to the drone.
TLDW: The total length of all the blood vessels in the human body is not 60,000 miles or 100,000 km as widely reported, but only 9,000 - 19,000 km. An excellent discussion by Kurzgesagt of how misinformation spreads on the internet.