Found a better solution:
Keep your current event graph as is. just add this modification.
Before calling ‘Toggle Visibility’, add a branch and put ‘Is Visible’ node into the the condition connector. Plug a reference to Light into the ‘Target’ connector of ‘Is Visible’. Then connect ‘False’ connector into the ‘Toggle Visibility’ node.
The advantage here is, if your light somehow got turned-off by some other event, when the player again comes into the trigger area, it will turn ON again. IF you destroy the trigger volume, this wont happen