To dream that you are on a swing suggests that you are comfortable and gratified with your current position and situation in life. It can represent different stages that you are entering. As well, it may imply that you want to experiment with your sexuality.
To see a swing set in your dream refers to your youth and your desire to avoid obligations. Perhaps you need to take a break from the pressures of your life.
To dream that you are swinging indicates that you are undecided on a certain issue and you need to reach a decision.