From "Mysteries of The Unknown"

The setting: a hot August morning in 1971 near the city of Cordoba in Southern Spain. A child sees a human face spontaneously appear on a pink floor tile -- a face with troubled features. When the family tries to rub away the face, they are horrified to see the eyes opening wider. The owner of the house tears up the floor and replaces the sinister tiles with concrete. Three weeks later a second face emerges.

Local authorities order a section of the floor cut away and uncover the remains of a medieval cemetery. Meanwhile, a third apparition appears, then a forth, then a series of faces. The kitchen is locked and sealed. Four more faces, including that of a woman, appear in other parts of the house. Then, just as suddenly, each melts away. Even the most cynical of experts are unable to prove the images are the work of human hands. The only hypothesis? The house was once the scene of a tragic and dreadful incident, perhaps connected with some form of medieval witchcraft.

Solution: UNKNOWN.