We had a fundraiser recently and one of the competitions was a Chocolate quiz. Cryptic clues with the answers as names of chocolate bars. The people pay to buy the quiz sheet, hand it in to you, and at the end of the fair you announce the winner, picked out of a hat if there’s more than one.
Also the ones that sell out quickly are the bottle stalls. Get lots of donations of bottles of food and drink. They all have raffle tickets on them, usually with the numbers ending in 0 or 5. All the other tickets are put in a bag and people pay to pick a ticket and if they get one that matches an item they get to keep the item. We include bottles of wine but you may need to exclude alcohol for a high school event….
Likewise the raffle. Get donations of prizes then sell tickets. Pick them at the end of the fair. Get local businesses to donate prizes – our local restaurant donated a meal for 2 and the hairdresser gave a free haircut.
Another one that does a very brisk trade is the games stall. People donate toys and games and you sell them. Especially good for younger kids.
Face-painting usually does well but three or four painters otherwise queues put people off.