Prepare the "lie detector": You can create a fake lie detector using cardboard or poster board. Draw some buttons, lights, and a display panel. Make it look whimsical and festive.
Wear a Santa hat: Put on a Santa hat to enhance the Christmas theme.
Set the stage: Gather friends or family and let them know that Santa is going to conduct a special lie detector test to see who's been naughty or nice.
Ask fun and lighthearted questions: Come up with amusing questions related to the holiday season, such as "Have you ever peeked at your presents before Christmas?" or "Did you eat any cookies meant for Santa?"
React playfully: Regardless of their answers, react in a lighthearted manner. You can make jokes, laugh, and keep the atmosphere fun.
Remember, it's crucial to consider the personalities and comfort levels of the people involved. Ensure that the prank is light-hearted and doesn't make anyone feel uncomfortable. Pranks should be done in the spirit of fun and camaraderie, and it's important to be mindful of others' feelings.

Santa Lie Detector prank game.
Christmas Truth Test prank detector.
Naughty or Nice Detector.
Claus Credibility Scanner Prank.