Ghostlore states that the spirit of Mabel herself haunts the theater but due to the fact she passed away even before the theater was built, we speculate this.
Several employees have reported their equipment being tampered with and passerbys have seen lights and shadows of figures in the windows even after the theater has been closed up and all the employees have left.
Whatever the case is, I have taken a tour thru the Victorian theater and thought it was absolutely GORGEOUS. Even if you don't believe in the ghostlore, go take a tour there, it's worth it!