Massachusetts General Laws Part I. Administration of the Government (Ch. 1-182) Ch. 140, § 183

No person shall darken in whole or in part the hall, room, piazza, roof garden or other place in which a public dance required to be licensed under section one hundred and eighty-one is held, or any stairway, anteroom or passageway connected therewith, during the progress of a dance therein or until all persons except the proprietor and his employees have withdrawn from the premises. The degree of light required in such places shall be fixed by regulations prescribed by the commissioner of the division of occupational licensure, copies of which and of this section shall be conspicuously posted in every such place. Violations of this section shall be punished by a fine of not less than one hundred nor more than one thousand dollars.