If you want to do it like that, why use switch at all? 🙂 Anyway you should read the manual how to use the switch because that is wrong syntax that you have there.
Switch in its simplest is:
switch($config)
{
case 'something':
// code
break;
case 'something else':
// code
break;
default:
// if its not any of the above, print, set or return error
break;
}