The 34-year-old actress claims she had a supernatural scare when she was staying on the farm of 'Along Came Polly' star Bryan Brown with an ex-boyfriend.
Rose - who stars as the mother of a haunted family in new horror movie 'Insidious: Chapter 2' - made her frightening revelation when quizzed if she'd ever had a ghostly experience while appearing on the 'The Tonight Show with Jay Leno'.
She recalled: "I had an incident once with an old boyfriend of mine like 10 years ago. We were staying at Bryan Brown's farm, a very iconic Australian actor, and we were staying in the little shed outside the main house and we were under a mosquito net.
"We went to sleep and then in the middle of the night my boyfriend at the time woke up, shouting, 'Ah get away, get away, get away, get away.' Then I was like, 'What's wrong, what's wrong?' He said there was a man, he came to the door and he was standing right there ... he was looking at us and he was coming for us.
Then the next day we asked Brian and he said, 'Oh yeah ... he's here all the time. He's a local. It's a ghost. He just shows up."
Although 'Bridesmaids' star Rose didn't see the spectre she insists she isn't afraid of ghosts and is ready to meet a spirit.
She added: "I've never seen one but I'm ready. Ready to go, ready to roll."
The Australian actress is convinced her apartment building is haunted because it was previously a funeral home before it was converted into homes.
She said: 'My apartment building in New York is actually an old funeral home ... but I've never seen one (a ghost) there so I don't think they like me."