Please note that in answering this question I am not creating an attorney-client relationship and that this answer is for educational purposes only. As to your question, you need to apply RCW 59.18.150. Here's the link: http://apps.leg.wa.gov/RCW/default.aspx?cite=59.18.150. Here is the key part in regards to your situation:
(5) The landlord shall not abuse the right of access or use it to harass the tenant. Except in the case of emergency or if it is impracticable to do so, the landlord shall give the tenant at least two days' notice of his or her intent to enter and shall enter only at reasonable times. The tenant shall not unreasonably withhold consent to the landlord to enter the dwelling unit at a specified time where the landlord has given at least one day's notice of intent to enter to exhibit the dwelling unit to prospective or actual purchasers or tenants. A landlord shall not unreasonably interfere with a tenant's enjoyment of the rented dwelling unit by excessively exhibiting the dwelling unit.
(6) The landlord has no other right of access except by court order, arbitrator or by consent of the tenant.
(7) A landlord or tenant who continues to violate the rights of the tenant or landlord with respect to the duties imposed on the other as set forth in this section after being served with one written notification alleging in good faith violations of this section listing the date and time of the violation shall be liable for up to one hundred dollars for each violation after receipt of the notice. The prevailing landlord or tenant may recover costs of the suit or arbitration under this section, and may also recover reasonable attorneys' fees.