53 Pa. Stat. § 13377
If any person or persons shall wilfully neglect or refuse to appear, or having appeared shall refuse to testify, or produce any books or paper writings, in his, her or their possession, or before either branch of the councils of cities of the first class, or any committee of either branch of the same, or before any joint committee thereof, after he, she or they shall have been duly served with a subpoena requiring him, her or them, so to do, it shall be lawful for such councils or any committee thereof, through its chairman or presiding officer, to present a petition to the court of common pleas of the county wherein such person or persons reside, setting forth the fact of the service of such subpoena and of the refusal to testify in obedience thereto, and the questions it is proposed to propound, and thereupon the court shall grant a rule upon the person or persons referred to to show cause why an attachment should not issue against him, her or them for contempt; and upon the return of the rule, if no sufficient cause be shown to the contrary, an attachment shall issue as prayed for in the petition according to the practice of such court in like cases of contempt for disobedience of its process: Provided, That in rendering judgment the court shall have regard as well to the pertinency and propriety of such questions, as to the regulating of the subpoena and the service thereof.
53 P.S. § 13377