I was internet acquainted with a homeless guy who did this for a while. I asked him about it as research. Because of my medical situation, I'm really not suited to this kind of work. But even if I were, I would have absolutely no idea how to get started.
I was fascinated by the fact that he knew how to find these unadvertised jobs in a community he had never been to before. Even after him describing it to me, I don't think I would have any hope of figuring it out. I imagine a lot of people whose experience is limited to formal job applications would have no idea how to start. Many would have no idea this is even a thing.
I wish I knew the right thing to say or questions to ask or whatever to use this as some opportunity to gather resources for another angle of approach to write about. I don't. This is wholly alien to my experience.
I think that's probably part of the problem in this country. Casual work connections of this sort used to be more common. Now, it's like only immigrants know how to do this. Most Americans don't.
That's not laziness or whatever. More like a blind spot.