A second, unrelated sense of the word maggid belongs to Jewish mysticism rather than to public preaching: a maggid in this usage is a disembodied voice, angelic or drawn from the personified Mishnah itself, that speaks through a kabbalist during study or trance and delivers instruction understood to come from beyond the recipient's own reasoning.
The most fully documented case is Joseph Karo, the sixteenth century halakhist best known for codifying the Shulchan Aruch, who kept a diary, later published as the Maggid Mesharim, recording decades of nightly visitations by a maggid he identified with the spirit of the Mishnah, which praised, corrected and urged him toward ascetic practice and eventual martyrdom.
Historians of Safed kabbalah treat Karo's maggid as a genuine and well attested phenomenon of his religious life rather than as invented after the fact, since contemporaries in his own circle, including Moses Cordovero, referred to it during his lifetime. This mystical maggid should not be confused with the preaching office of the same name, and the coincidence in terminology reflects a real linguistic ambiguity in Hebrew rather than a single unified role; a preacher who moved crowds with his voice and a disembodied instructing voice heard by a single mystic share only the word that named them, magid, one who tells or relates.