The old Imbrie farmstead (now a McMenamin's pub) in Hillsboro has had a reputation of being haunted for a while now. Also, ghost stories are told about the old Meier and Frank Building in downtown Portland itself. Knew people that worked at both places that had stories to tell about them both. The purported haunting at the Imbrie Farmstead occurs on the second floor. I believe the Meier and Frank Building has problems on its office level, iirc, and my friend said that it was thought to be the ghost of a janitor.
The haunted lighthouse on the coast would be the Yaquina Bay Lighthouse. Iirc, it has ghost stories attributed to it. I've heard stories about the underground area in downtown Portland, too. One of the older buildings at Portland State University also has a purported ghost in it. I think it was Lincoln Hall but it could've been Shattuck. I can't remember.

Mt. Calvary Cemetery off of Barnes Rd. is also purported to being haunted but eh, it's a cemetery so no great surprise there...
My family thinks that we lived in a haunted house in one of the Portland suburbs. The house was definitely on the peculiar side. We would all hear footsteps in the attic at night and the house would fill with very pungent odors of cologne or something rotting. Objects would disappear and reappear in the strangest places as well. The house, though, was peculiar to begin with. All the interior bedroom doors had bolt locks (this was an expansive ranch home) and evidence that somebody had lived in the attic at one time. Very weird for the neighborhood (upper middle class). The previous owner had disappeared.