25 Pa. Stat. § 3457
In each of the aforesaid second, third, fourth and fifth classes, the petitioners shall be registered electors who voted at the primary or election so contested. In cases of the third class, each petition shall be verified by the affidavits of at least ten of the petitioners; in the second, fourth and fifth classes, by the affidavit of at least five of the petitioners. Such affidavits shall be taken and subscribed before some person authorized by law to administer oaths, and shall set forth that they believe the facts stated therein are true, that according to the best of their knowledge and belief, the primary or election was illegal and the return thereof not correct, and that the petition to contest the same is made in good faith.
25 P.S. § 3457