Hi man , you can do the array in the blueprint but its more clear and easy if i show you how do it in the editor.
Otherwise you have to script some evaluation to check wich is the light you want and so on…
Create a variable in your Switch, as show , be sure that is selected as Array and is editable.
Now, hit the Compile button. Is important , otherwise you cant edit the array.
Now go in the editor , and select your switch . in the detail panel on the right you will see that now Array is avaible.
Expand it and add as much light you need. use the select scroll down to select a light and check with the Maghifier button if is the right one.
Then you can do 2 scripts.
Use the for each loop , will use every reference in the array to put them all on or off.
Otherwise use a loop, and you have to say from wich one to wich one do what.
Be aware that the first Pointlight is at the array_0 … as shown in the upper right part of my screenshot.
Hope its clear 
