The key to exercise solutions in chapter Unit 30 - May and might 2 for the textbook English Grammar in Use with authors Raymond Murphy from Cambridge University Press
Question
Write sentences with might not.
Answer
Liz might not come to the party.
I might not go out this evening.
We might not be able to get tickets for the game.
Sam might not be able to go out with us tonight.
You can use may instead of might in all these sentences.