Wyo. Stat. § 2-6-301: Filing and contents of petition to revoke.

After a will has been admitted to probate, any person interested may, within the time designated in the notice provided for in W.S. 2-6-122 or 2-7-201, contest the will or the validity of the will. For that purpose he shall file in the court in which the will was proved a petition in writing containing his allegations against the validity of the will or against the sufficiency of the proof, and praying that the probate be revoked.