The Changeling was a 1980 Canadian horror film.

After the tragic death of his wife and daughter, a music professor, John Russell (played by George C Scott) is staying at a Seattle mansion and becomes involved in an old mystery.

Investigating the history of his house (which seems to be haunted), John finds out that a boy was murdered there in 1906 by his father. The father then replaced the dead boy with one from an orphanage, then took the lad off to Europe claiming to be seeking a cure for his son’s illness.

The adopted boy is now an old man, a US Senator, and patron of the historical society which owns the house where John Russell is living.