Over Her Dead Body (2008)

After his fiancée, Kate (Eva Longoria Parker), dies in an accident on their wedding day, veterinarian Henry (Paul Rudd) grows depressed. To help him move on, his sister has him visit psychic Ashley (Lake Bell) and gives her Kate's diary. Ashley uses the journal's details to convincingly deliver the fake message that Kate wants Henry to move on. However, Kate's ghost is watching over Ashley and Henry. Furious when they fall for each other, she vows to sabotage their relationship.