살인마(1965) / A Bloodthirsty Killer ( Sal-inma )

A man finds a portrait of his long-dead wife hanging in a gallery, and taking it home lets loose a ghost that reaches his family through a cat. A painter's diary eventually spells out how she was poisoned and who the vengeance has been working its way through since.

Why it's free: Free on the Korean Film Archive's own channel; KOFA holds the rights to the restorations it publishes.