This technique is always good for a laugh and sometimes brings down the house.
Invite two people on stage that have opposite roles. It works particularly well with husband/wife , boyfriend/girlfriend, employee/boss.
Have them play the role of the other person, i.e., the husband acts as if he is the wife and vice versa. You could have some funny props like a wig to put on the guy and give the wife a handyman's tool belt, etc. (In many cases you will find it hard to continue at this point because everyone will be laughing so hard just from the site on stage.)
Brainstorm questions to have the pair ask each other and have them answer as if they were the other person. Write these out for both of them.
Have the husband (who is playing the part of the wife), ask the wife who is playing the part of the husband, "where do you think you are going with those golf clubs?" Either write funny answers for them like, "I was going out to the garden to use them to hold up the tomato plants" or just let them ad lib.
You could have competition between pairs for the best answers and give out prizes.
This is a very fun technique, but you really need to brainstorm on some funny questions and answers in case the people on stage aren't fast enough to think up funny stuff on their own.