Change your design. Polling is bad, and not necessary.
Attach IBActions to each switch.
Make the switch's action methods set properties. If you have a lot of switches you can put tags on each switch and have a single method that handles all of them.
Then you can either create custom setters on your properties, or use key-value observing to watch for changes in the host properties. Take a look at the "Introduction to Key-Value Observing Programming Guide" in the Xcode docs for a description of how this works.
Which approach is better depends on the details of your application, plus your personal taste. KVC is a little slower than other methods, but it works well.