When a visitor or member visits my site they sometimes appear as ME! they have access and can post as ME as well. This is a major concern since my profile is a Super Admin! They dont need an account, they simply visit the home page and they have access under my profile.
Has ANYONE come across this before and if so, what was the fix? I need help quick befor my site gets destroyed!
Sounds very much to me like your site has been hacked. Can't think of any other possible explanation.
Take it offline and rebuild it. This time prioritise for security as you are obviously a target for some reason. Get help from a Joomla security specialist. Install sh404SEF as a quick fix, it blocks a lot of these attacks.
You also need to worry about the search engine response since if you've been hacked it's for a reason. Sometimes they put malware downloads on your site and if that happens Google will take you down.