§ 94. General powers and duties of commission in respect to telegraph corporations and telephone corporations. 1. The commission and each commissioner shall have power and authority to administer oaths in all parts of the state to witnesses summoned to testify in any inquiry, investigation, hearing or proceeding and also to administer oaths in all parts of the state whenever the exercise of such power is incidentally necessary or proper to enable the commission or a commissioner to perform a duty or to exercise a power.

2. The commission shall have general supervision of all telegraph corporations, telephone corporations and telegraph lines and telephone lines within its jurisdiction as hereinbefore defined and shall have power to and shall examine the same and keep informed as to their general condition, their capitalization, their franchises and the manner in which their lines and property are leased, operated or managed, conducted and operated with respect to the adequacy of and accommodation afforded by their service and also with respect to the safety and security of their lines and property, and with respect to their compliance with all provisions of law, orders of the commission, franchises and charter requirements. The commission shall have power either through its members or inspectors or employees duly authorized by it to enter in or upon and to inspect the property, equipment, buildings, plants, factories, offices, apparatus, machines, devices and lines of any telegraph corporation or telephone corporation.

3. The commission and each commissioner shall have power to examine all books, contracts, records, documents and papers of any telegraph corporation or telephone corporation and by subpoena duces tecum to compel the production thereof, or of duly verified copies of the same or of any of them.

4. The commission shall require, with respect to any charge for the installation or initiation of service of a residential telephone line, or any nonrecurring maintenance service charge with respect to a residential telephone line or equipment, that any telephone corporation imposing such a charge offer a plan for the deferred payment thereof in installments over a period of up to one year. For the purposes of this subdivision, charges for initiation of service are charges for the connection of service including but not limited to charges for central office line, premises visit, inside wire and jacks, and any related service.