Mentally unstable neighbor. What recourse do I have?

I recently bought and moved into a house, and my neighbor has become an issue.

It’s very clear that he’s mentally unstable. He will be out pacing on his porch throughout the day, usually without a shirt on. The house is in a dilapidated state of neglect. Obviously he can do what he wants on and to his property, but he yells at nothing in particular throughout the day.

The main issue is his constant angry yelling. As I’m typing this at 11:45 pm, he’s yelling in short bursts every few minutes. But this happens at any hour of the day. Morning, afternoon, or evening, it’s unpredictable. Currently I can hear him in my house as I’m trying to sleep. Most of the time it’s just angry moaning, but sometimes he’s actually yelling words.

I’ve been told by my neighbors that he lives alone, but I don’t know how he supports himself or if someone is supporting him. I also don’t know if anybody ever checks on him. I’ve also been told he’s more of a hazard to himself than anybody in the neighborhood, which is good.

He very much needs help. This has become an uncomfortable living situation for me, and it’s almost making me regret this home purchase.

What options do I have? Anybody ever dealt with something like this?