Call The Midwife star Charlotte Ritchie is convinced the set of the maternity drama is haunted.

The British actress is adamant one of the historic buildings where the hit show is filmed is inhabited by ghosts, and she is terrified of encountering a ghoulish presence while working.

She tells U.K. newspaper the Daily Mirror, "I can't go in (the toilets) alone. When you go in you get this strange feeling that you're not alone. It's so spooky and surreal... The props guys told me they heard voices in the attic room when there was no one else up there. One came down and he was properly white. Poltergeists really get me... It's not a question of belief - whether it's true or not it definitely affects my life."

The final episode of Call The Midwife series four airs in the U.K. on Sunday (06Mar15).