Mo. Rev. Stat. § 476.290: Judges not to practice law — exception, municipal judges.

No judge, except a part-time municipal judge, shall practice or act as counselor or attorney in any court within this state nor shall any clerk or deputy clerk, while he continues to act as such, plead, practice or act as counselor or attorney in any court within the county for which he is such clerk or deputy clerk, in his own name or in the name of any other person, under any pretense whatever.