A writ of habeas corpus must be served by the sheriff, deputy sheriff or some constable of the county in which it is issued or in which the person on whose behalf it issued out is imprisoned or detained, by delivering a copy to the person to whom it is directed and showing the original, if demanded. If such person cannot be found, conceals himself or refuses admittance to the officer, the writ may be served by leaving a copy at the place where the party is confined with any person of full age who, for the time being, has charge of the party or by posting it in a conspicuous place on the outside of the house or building in which the party is confined.