Pennsylvania constitution
Article V: the judiciary
Section 14

Effective immediately upon establishment of magisterial districts and until otherwise prescribed the civil and criminal procedural rules relating to venue shall apply to magisterial districts; all proceedings before aldermen, magistrates and justices of the peace shall be brought in and only in a magisterial district in which occurs an event which would give rise to venue in a court of record; the court of common pleas upon its own motion or on application at any stage of proceedings shall transfer any proceeding in any magisterial district to the justice of the peace for the magisterial district in which proper venue lies.