Jennifer Aniston fears there's a very familiar spook in her home.

The actress has told friends she was alone in her new Bel-Air mansion when she saw a ‘dark-haired woman' - that she was convinced was supernatural.

She apparently described the ‘ghost' as a ‘female...  tall, pale and thin with long dark hair and dressed all in black.'

Hmmm...

Jen wasn't scared when she saw the ghost ,' says a friend.

‘It was only there a couple of seconds before it disappeared.'

Jen, 44, apparently burst out laughing after saying it ‘was almost a double of Angelina Jolie', and is now busy researching the history of her home, bought earlier this year.