St. 225 & 221 were alerted for a reported Commercial Fire Alarm. 221 CHF arrived on scene finding a 3 story commercial apt with nothing showing, assuming Valmar Command. 221 Wagon arrived on scene with crew going to investigate with 225 Service. Crews located a pull station on the 1st floor that was tampered with. Crews reset the pull station and alarm with assistance of maintenance. Crews all returned in service.