A special township meeting may be held for the purpose of:
1. Electing township officers to fill vacancies that occur;
2. Authorizing expansion of the board of township supervisors from three to five members;
3. Removing an elected township officer;
4. Transacting other lawful township business whenever the supervisors or township clerk, or any two of them, or twenty percent of the freeholders of the township, shall file in the office of the township clerk a written statement that a special meeting is necessary; or 5. Whenever a special meeting is required by any other provision of the laws of this state.