If you know where the bug is, bug the bug with a high-frequency, white-noise, whatever machine. Or play music, talk softly, constantly go clack-clack on a keyboard... or just use a lot of pronouns so they can't tell what you're talking about.
Have a conversation with your boss. S/he is responsible for controlling the work environment. If you don't get a response from him or her, have a conversation with the police. Do that after obtaining a new job.