"He has inflated or exaggerated his role within the wider court system," said the judge.
"Inflation of ego has got him into this fix."
Casbolt had denied impersonating a police employee and carrying an offensive weapon.
Judge Lynch said the uniform he wore bore no police logo or wording and might have led a member of the public to believe "he worked for Corrections or Customs or the like".
"However, the circumstances would not lead people to believe that he was a police employee, nor am I satisfied that was his intention."
He said he applied "a good dollop of common sense" in deciding to dismiss that charge.
But he decided that the baton Casbolt was carrying - bought from a martial arts store - was an offensive weapon.
Casbolt referred to it as a "bite stick" and said he used it to deter dogs he might encounter when serving documents "to people who are not the friendliest".
Judge Lynch noted that the baton could also have been used on people, and said that Casbolt had no lawful authority or reasonable excuse to take it into the court building with him, as part of the uniform he handed over to the security staff at the door.
He was at the courthouse September 9 last year to swear an affidavit about a document having been served. He was stopped at the door and the gear was seized. He was charged. He said he had worn the gear to the courthouse on up to six previous visits.
The judge said he could easily have left the gear in his car, which he parked nearby. He was under no threat of attack as he made the court visit.
After Judge Lynch found the offensive weapon charge proved, defence counsel Elena Stavrovska said Casbolt would apply for a discharge without conviction at the sentencing hearing, which is scheduled for August 5. He remains on bail.
Casbolt has previously tried to set up a free street hospital service and a detoxification service. During the trial he told of working as a security guard, investigator and process server.