Congratulations! I had the same arcing problems , ever since I've moved in to this house. I knew it had to be a street light, but couldn't find the one causing problems. Turns out, I've missed a broken street light on closed factory yard next door, took numbers of the pole and filled in the PSNH online form. A week later my friends in the orange truck came and bye bye noise!
After 8 years, finally no arcing noise at night
Frits W1FVB