68 Pa. Stat. § 250.504-A
The tenant shall have a right to invite to his apartment or dwelling unit such employees, business visitors, tradesmen, deliverymen, suppliers of goods and services, and the like as he wishes so long as his obligations as a tenant under this article are observed. The tenant also shall have right to invite to his apartment or dwelling unit, for a reasonable period of time, such social guest, family or visitors as he wishes so long as his obligations as a tenant under this article are observed. These rights may not be waived by any provisions of a written rental agreement and the landlord and/or owner may not charge any fee, service charge or additional rent to the tenant for exercising his rights under this act.
It is the intent of this article to insure that the landlord may in no way restrict the tenant's right to purchase goods, services and the like from a source of the tenant's choosing and as a consequence any provision in a written agreement attempting to limit this right shall be void and unenforceable in the courts of this Commonwealth.
68 P.S. § 250.504-A