..... It is thought to be bad luck to drop a key and even worst to break one in its lock... The luck persevering powers of the key are kept in parts of old world Europe. . Tradition states that slipping a key under Infants pillow will protect them from evil and crib death, over all keep them safe while they sleep.

..... A Wife's tales of France has it, the owners of large bunches of keys are warned (specially graveyard caretakers ) not to jingle them to much on a wednesday, as this will make the owner go stalk raving mad.