Yes. Vitobha, considered to be a svarup of Lord Vishnu himself by Warkaris and Haridasa, sects based out of Maharashtra and Karnataka, can be considered to be non-brahmin and non-kshatriya form. Some traditions have Vithobha as a form of Shiva.
From the Wikipedia entry
Other legends describe Vithoba coming to the rescue of his devotees in the form of a commoner, an outcast Mahar "untouchable" or a Brahmin beggar. Mahipati, in his work Pandurangastrotra, narrates how Vithoba helped female saints like Janabai in their daily chores, such as sweeping the house and pounding the rice. He narrates how Vithoba came to the aid of Sena the barber. The king of Bidar had ordered Sena to be arrested for not coming to the palace despite royal orders. As Sena was engrossed in his prayers to Vithoba, Vithoba went to the palace in the form of Sena to serve the king, and Sena was saved. Another tale deals with a saint, Damaji, the keeper of the royal grain store, who distributed grain to the people in famine. Vithoba came as an outcaste with a bag of gold to pay for the grain. Yet another story narrates how Vithoba resurrected the child of Gora Kumbhar (potter), who had been trampled into the clay by Gora while singing the name of Vithoba
P.S. While Wikipedia is not considered a valid source, I have only cited that section of wikipedia which has reference to the primary text
As Wikipedia entry says , the above events are mentioned in Paduranga stotra by Mahipati. Scanned images ( in marathi) can be found here