Idk how much help this will be, but I would say something along the lines of:
Dear —,
The street light have been an issue for a good while now. Here are some of many reasons why we should have proper lighting when it’s dark outside: there has been theft. Theft of personal belonging and even children if it doesn’t get fixed. Accidents. Without light, cars cannot see that far with just head light so they could get in a serious car accident. There could also be a person getting injured. Whether they fall because they cannot see, or they run into something. This is a serious problem and hope it can get fixed.
Sincerely, —