You can add a collision to the flashlight bp (assuming it is an actor), which on overlap will toggle another boolean in your character blueprint via a blueprint interface (or casting, if you’re more comfortable).
You may need to watch some youtube tutorials on interfaces and overlap events, but I laid out the basics below:
I couldn’t come up with proper function names or properly place the final boolean and branch (last photo) as I don’t fully understand the concept of restricting the flashlight’s use to a certain spot. But, as long as it makes sense to you, you should be able to work through it.