Patsy was a holographic character from County Meath in the Fair Haven holoprogram, set in 19th century Ireland.
Old Patsy had told Seamus a story about a village called Kilmanin, which had vanished in 1846 after the arrival of strangers. This was told by Seamus to other Fair Haveners to convince them, the new villagers (in fact crewmembers of the USS Voyager) were spirit folk. (VOY: "Spirit Folk")