Who the 'Good People' are:

I ... asked John what sort of race the 'good people' are, and where they came from, and this is his reply: -'People killed and murdered in war stay on earth till their time is up, and they are among the good people. The souls on this earth are as thick as the grass (running his walking stick through a thick clump), and you can't see them; and evil spirits are just as thick, too, and people don't know it. Because there are so many spirits knocking about they must appear to some people. The old folk saw the good people here on the Hill a hundred times, and they'd always be talking about them. The good people can see everything, and you dare not meddle with them. They live in raths. and their houses are in them. The opinion always was that they are a race of spirits, for they can go into different forms, and can appear big as well as little.
From The Fairy Faith in Celtic Countries by W.Y. Evans-Wentz, p.32
Hyperspace Celtics