use of may and might

"May" is used for ask the permission eg. may I come in or may is used for possibility might is used for less possibility

May Used to ask for formal permission: May I come in? May I say something now? May I ask one question? Used to suggest something that is possible: She may agree with this plan. They may not be happy about what happened. It may shower tonight.

Might (past form of may) Used to suggest a smaller possibility than may does (actually, might is more common than may in American English) : He might have finished it. I might go see a doctor. I might not come this time. It might be right. You might have lost it. The store might have been closed today.