I , from my personal profile had written some content over a fan page, and its access is automatically to the public. I'm also unable to find out the option to change it. Even, on facebook help section, I'm unable to find out that how do i change the view to non-public? Any ideas...
I think you can't do it. Even I am facing the same problem. If you have to share something personal then don't share on your page instead share it on you wall.