As hams, I believe that all we can do is to provide him with information, perhaps mail him an FCC or ARRL packet of RFI and part 15 regulations. If there is a local radio club, possibly they have a TVI group who can offer him advise, if he wants it. This works two ways also. I try to understand my neighbors also. For example, one neighbor lady in our subdivision circulated a petition to ban a neighbor's rooster who would get very noisy at perhaps 2 or 3 am in the morning. During our summer here in Alaska it never gets dark for months, and sunrise is very early for a few months. We sleep with our windows open, so yes, we heard the rooster greeting us in the morning, but we chose to live in this semi-rural area, so refused to sigh her petition. We have had sled dog teams within earshot of our house, but again never complained. I had neighbors help me erect two of my towers, but also provided them with firewood when their furnace failed during a storm. Several times their furnace failed during winter storms when they were out of state, but I managed to do a temporary fix until they returned and had proper furnace repair. We have each other's house keys, and try and look after things if they are out of town. When I had open heart surgery, many neighbors offered to shovel our stairs and walkway, and we thanked them and let them do it a few times, even though my wife is healthy and enjoys shoveling snow (like I do) in the winter.
I disagreed with one local ham who lives right in town and ran a KW. He caused much trouble with the PA system in several local establishments including the senior citizen center. He refused to work with them and just cranked up his power, but he died a little later, so problem solved. Rick KL7CW