A. "May" and "might" are sometimes used interchangeably to express possibility or probability. Here are some places where "might" would be used rather than "may."
* to express permission, probability, or possibility in the past -- My brother might have said that.
* to express a present condition contrary to fact -- If you have enough money, you might be able to get good tickets for the show.
* to express less probability that "may" -- I might go (but I don't really expect to).