Wash. Rev. Code § 66.20.120
Any person in charge of an institution regularly conducted as a hospital or sanatorium for the care of persons in ill health, or as a home devoted exclusively to the care of aged people, may, if he or she holds a special permit under this title for that purpose, administer liquor purchased by him or her under his or her special permit to any patient or inmate of the institution who is in need of the same, either by way of external application or otherwise for medicinal purposes, and may charge for the liquor so administered; but no liquor shall be administered by any person under this section except to bona fide patients or inmates of the institution of which he or she is in charge and in cases of actual need and every person in charge of an institution who administers liquor in evasion or violation of this title shall be guilty of a violation of this title.
RCW 66.20.120