We live on a small ranch in central Texas, several miles from the nearest small town. There's an unspoken code out here that even if you don't really know them, you always help out your neighbor in an emergency. A cow breaks through a fence, a grass fire starts, all kinds of things happen. That person banging on your door could have been a neighbor having some kind of late-night emergency; a spouse unconscious on the floor, a horse tangled in some barb wire, etc.
Of course, it also could have been a criminal as well, I'm not minimizing that possibility. But the point has been well made that you need to be sure what you're doing.