How do I control a light intensity by using dragging an object function?

Hi Everyone.

I am facing a challenge in my learning of unreal engine. I am trying to create a function where the intensity of the light is controlled by dragging an object like a switch. I can simply toggle the light by using another object. I was stuck when trying to make a light gradually brighten up. Does any one have any pointers or ideas in how to do this?

Thanks in advance.
Chan

Problem solved