In the 1940s Nikolai Kaario, an artist and a decorative painter, discovered seemingly old images on house walls in Turku, Finland. These findings generated considerable interest in the press. The Archeological Commission of Finland evaluated them, concluding that the images were not medieval and were made unconsciously by Kaario. Despite the Commission’s findings, the dispute did not abate. Severa other people also found similar images on the walls of old houses in Turku, even after Kaario’s death. The authors review these events and suggest that they reflect the effects of pareidolia.