Sarah Paulson on How 'Ratched' Predates 'One Flew Over the Cuckoo's Nest' (Exclusive)

ET sat down with the 'Glass' star to talk about her new film, in theaters Jan. 18. Paulson also dished on her upcoming project with Ryan Murphy, 'Ratched,' and how it is more of a prequel to 'One Flew Over the Cuckoo's Next.'