The Sons of Erin Society Building  is the headquarters of the Sons of Erin Society.
Around the turn of the century, the officers of the Sons of Erin imprisoned a Leprechaun in a sealed Mystic Circle built in a secret room near an office in the Sons of Erin building. On the weekend before St. Patrick's Day in 1997, a restoration project was underway in the Sons of Erin Society Building. A construction worker named Mr. Murphy triggered the secret room passage by removing a pipe from a small rack. Murphy disturbed the circle and freed the Leprechaun. After the foreman Mr. O'Malley heard a commotion, he rushed over to briefly see the Leprechaun before it vanished. The Extreme Ghostbusters were called into investigate. They took readings, statements, and confiscated a fragment of the Blarney Stone. Egon Spengler later returned to the Sons of Erin Building and got P.K.E. readings off a plaque with names of the club's officers. Egon collected a large amount of books about to be thrown out and uncovered background data on the Leprechaun.
- In the outline, the Sons of Erin Society building was originally a vast castle-like building, imported from Ireland at the turn of the century, and preparing to send it to an amusement park in Florida. 
- ↑ Egon Spengler (1997). Extreme Ghostbusters- The Luck of the Irish (1997) (DVD ts. 08:37-08:41). Sony Pictures Home Entertainment. Egon says: "I'm not going with them, I'm going back to the Sons of Erin Building."
- ↑ Wachtel, Brooks (1997). Extreme Ghostbusters "The Luck of the Irish" (Outline 1997) (Outline p. 1). Line reads: "Workmen are disassembling a vast castle-like building, imported from Ireland at the turn of the century, to transport it to an amusement park in Florida."