Sometimes dreaming about a famous actor or actress may be a wish-fulfilling dream, or it could hold important messages about ourselves.
We admire celebrities and may wish to have some of their characteristics.
Consider the personality traits or any other trait that attracts you to that person.
If you are dreaming that someone is acting, you may be dreaming about yourself.
The dream could be pointing out some of the roles that you play in life. Among the many roles we play are parent, spouse, lover, student, professional, etc..
We behave somewhat differently in each of those roles.