Switch Piston Trigger

Realatively new to CoRE and not a programmer but having trouble with something that I thought would be pretty straight forward. I want to trigger a piston when a light switch is turned on. I’ve selected ‘switch changes to on’ as my If event. When I turn the switch on, the piston runs, but it also runs when I turn the switch off. No option that I select will run the piston ONLY when the switch is turned on. The piston always runs when it is turned off too.

“Switch changes to On” has 2 states (evaluations): True and False. Since the conditional is a Trigger, it must be evaluated on Switch change. Just make sure any actions are in the appropriate THEN (true) or ELSE (false) clauses, and you should be fine. Of course, ELSE is optional.