What about a secretary, janitor, shrink (psychiatrist), collar (priest), mailman, or carney (carnival worker) or a person with a degree in culinary arts known as a "cook."
None of the above set well either. Interestingly, most police officers seem cool or ok with being referred to as a cop. Prison guard definitely doesn't go over well with corrections officers. That's a tough job and wears on people mentally, emotionally because they are dealing with people everyday with the intent on zapping them emotionally, mentally, and sometimes physically.