On April 22, the Washington state legislature passed HB 1474. It provides that in all cases, non-partisan state office elections will always appear on the November ballot. Under current law, for state offices that are non-partisan, if anyone gets 50% or more in the August primary, the person is deemed elected.
But under the bill, the state non-partisan offices will always appear on the November ballot, even if someone got 100% of the votes in the August primary. Washington state has write-in space on the November ballot, so even if only one candidate will appear on the November ballot (because only one person filed), in theory the person could be defeated by a write-in candidate in November. Here is the text of the bill, which is very short.
The non-partisan state offices are Superintendent of Public Instruction, and all three levels of state judge (Supreme, Appeals, and Superior). Here is a news story about the bill. Thanks to Rob Richie for the link.