Wash. Rev. Code § 11.125.160
(1) Except as otherwise provided in the power of attorney, the following persons may bring a petition described in subsection (2) of this section:
(2) A person designated in subsection (1) of this section may file a petition requesting the court to construe a power of attorney or grant any other appropriate relief, including but not limited to:
(f) Removal of the agent on a determination by the court of both of the following:
[ 2016 c 209 s 116.]