activating (trigger volume/matinee) by viewing it by a flashlight (spotlight merged with fps player camera )

-im making a fps/horror game and i want to make a matinee activated ( like when you enter trigger volume to activate the matinee )
by viewing a trigger volume or an object…
i thougt making a invisble spotlight on the player camera and make some specific trigger volumes / objects activeting some matinees if the spotlight light distance touches the specific trigger volumes / objects
the problem is i want to know how to do it