Sister singing duo Aly and AJ Michalka have a loon.

A man has been arrested and charged with stalking the Disney stars after the girls woke up in the middle of the night to find the stranger prowling around their Calabasas, CA. home.

Aly and AJ — who now go by the name 78violet professionally — previously obtained a restraining order against Caesar Brantley, who was nabbed by cops violating that protective order outside the girls’ gated community early Thursday. Brantley has been charged with a felony charge of stalking and a misdemeanor charge of violating the sisters’ restraining order.