Mirrors do have a special fascination for authors. Already in the old days, when the fairy tales were spun, a mirror played an important role in the tale of Snow White and the Seven Dwarfs.
And isn't it in a mirror Christine Daée sees the Phantom of the Opera for the first time??? Through this mirror he talks to her and takes her away to his world of darkness, where music reigns. When his love doesn't have a happy ending, he destroys the mirror...
Also I used a mirror in my short tale Face in the Mirror. A young runaway breaks into a deserted mansion and find solace talking to the face she sometimes sees into her bedroom mirror.
Yes, mirros take an important plays in lots of books. Just a day or so ago I came across a wonderful book, named The Mirrors at Barnard Hall. I sometimes browse the Amazon Kindle shops for deals, and I've often found that books which are quite cheap (3 $ or less) are often good and interesting reads. This way I get to know authors and their books, and the above mentioned is one I'd like to recommend.
If you are into a good story in which ghosts and romance are galore, then you must also read Jenny Hickman's book. It's the story of Callista Franklyn, heiress to an enormous fortune which includes a manor house in England. Once, when she was a little girl, she stayed there for a few months, until her stepfather manages to send her off to America once more. When she finally returns to England, it is after the death of her mother and stepfather. Alone in her room, she stares into the mirror where once she met her best friend Tilly - and now meets Nick, Tilly's elder brother. I won't tell too much of the story, as it is one you'll read without pause. But I can promise you it's a beautiful story.