§ 478. Investigation of complaints by boards of managers. Whenever the managers, directors or trustees of any asylum, hospital or other charitable institution, the managers, directors or trustees of which are appointed by the governor and senate, or by the legislature, shall deem it necessary or proper to investigate and ascertain the truth of any charge or complaint made or circulated respecting the conduct of the superintendent, assistants, subordinate officers or servants, in whatever capacity or duty employed by or under the official control of any such managers, directors or trustees, it shall be lawful for the presiding officer for the time being of any such managers, directors or trustees, to administer oaths to all witnesses coming before them respectively for examination, and to issue compulsory process for the attendance of any witness within the state whom they may respectively desire to examine, and for the production of all papers that any such witness may possess, or have in his power, touching the matter of such complaint or investigation; and wilful false swearing by any witness who may be so examined is hereby declared to be perjury. A subpoena issued under this section shall be regulated by the civil practice law and rules.