Yes. You must contest the ticket. Under Washington law, all infractions - traffic and non-traffic - are deemed committed UNLESS contested.
This answer is given merely for informational purposes and does not create an attorney-client relationship. For specific advice, contact an attorney in your state to see if working together makes sense.
If the ticket is not yet on your record and you still have time, the only way to keep it off your record is to request a Contested Hearing so you can challenge it. If you have not requested one, do it quick because there is normally a 15 day time period.