From publisher blurb:
The Pneumaphagoi, or the Eaters of Spirits, are a loose organization of individuals that share one bizarre common activity: eating ghosts. Learned from ancient texts or from begrudging tutors, the secrets of trapping and consuming spirits yield numerous benefits, and thus appeal to people with a wide variety of motives. For some it is the thrill of consuming an exotic substance, which like all highs is fleeting and ever more elusive; for others it is the power, which quickly fades. The promise of longevity draws some, although the added years can be gray and thin. Others have more noble motives in their quest to destroy the undead, a nobleness that is quickly clouded by the addictive nature of the task. Many are the paths to becoming an Eater, few that lead away.
The Pneumaphagoi is an 11-page PDF detailing a drop-in organization for your d20 Fantasy game, complete with history, tenets, organizational structures, ways of joining, and ready-to-use NPCs. It also includes six new feats, two new spells, two new incantations, and all the necessary rules to bring spirit eating into your campaign along with the possible consequences.