Is there a way to set a specific slide to be a screensaver?

A lot can be accomplished with JavaScript, but to get you an ideal solution, it'd be worth better understanding the purpose of the "screensaver" and how it's supposed to function. Is this a facilitator's presentation that you want to time out? Do you anticipate learners walking away from their screen for a while but not locking their computer, and you want to stop other learners from seeing what they've written? The specifics of your situation will inform the solution, and there's probably a simpler solution than a full-fledged screensaver.