Washington Revised Code Title 29A. Elections § 29A.24.171. Vacancies in office

(1) If, prior to the first day of the regular filing period, a vacancy occurs in an office that is not scheduled to appear on the general election ballot, leaving an unexpired term for which a successor must be elected at the next general election, filings for that office shall be accepted during the regular filing period. The filing officer shall provide notice of the vacancy and filing period to newspapers, radio, and television in the county, and online. The position shall appear on the primary and general election ballots unless no primary is required or unless a candidate for superior court judge is entitled to a certificate of election pursuant to Article 4 [IV], section 29 of the state Constitution.

(2) If, on the first day of the regular filing period or later, a vacancy occurs in an office that is not scheduled to appear on the general election ballot, leaving an unexpired term, the election of the successor shall occur at the next succeeding general election that the office is allowed by law to have an election.