Possible Clues:

• Elaborate April fool
• April 1 event
• Deception in house, a sign of something wrong
• Playful fraud
• Something intended to deceive
• Deception such as the Piltdown Man
• The finding of a Virgin Mary-shaped gummy candy, e.g
• "The War of the Worlds" broadcast, notably
• Humorous deception
• Barnum's 'Feejee Mermaid,' e.g