Judges shall not testify voluntarily as a character witness.
Commentary:
Judges must not testify voluntarily as a character witness, because to do so may lend the prestige of the judicial office in support of a party for whom the judge testifies. Moreover, when a judge testifies as a witness, a lawyer who regularly appears before the judge may be placed in the awkward position of cross-examining the judge. A judge may, however, testify when properly summoned.
Ga. Code. Jud. Cond. 3.3