Don't take Legal Advice from Non-Lawyers, e.g. the Bank, or your Landlord
60-90 days after the Trustee's sale, the subsequent purchaser has standing to ask the local Superior Court to evict you. They have to file and serve a summons for unlawful detainer, complaint, motion for order to show cause, and an order to show cause requiring you to appear and show cause why a writ should not be issued.
The writ is the document that empowers the sheriff (NOT the purchaser) to evict you. The order to show cause is your opportunity to explain why you should not have to leave. You will lose this argument so don't raise it. Your options are more manageable if you move out and then sue your landlord.
What you cannot do is stay in the property after a writ has been sent to the sheriff for enforcement expecting that the sheriff will not evict you. They will. Maybe not immediately, but they will.
My other tip? If this happens to you, tell somebody. The local news station, your local newspaper. Hope this helps you. Elizabeth Powell
Lease or month to month?
If you have a lease, you can move out and sue your landlord for breach. If you don't have a lease, you can move out and sue for your landord's failure to provide proper notice to terminate your rental agreement.
If you have a real estate contract (you are buying the place but title is still in the seller) you will want to review Washington's newly revised law prohibiting equity skimming, also called Distressed Property Transactions.
Additional resources provided by the author
Google "Housing Justice Project" - they can steer you in the right direction.