On Method for a collider on another object.

Hi guys, I've just been wondering if I can call an On method (such as OnTriggerExit) on a script attached to another object? I'd just like to know if I'm wasting my time or not. In my case I have 2 walls sharing a script, and a ball jumping off of them. I wanna make the one that is jumped off of, be disabled (and the opposite one enabled). So is this legit?

 public Bouncer jumper;
 
 void OnTriggerExit2D (Collider2D other)
     {
 
         if (other == jumper.trig) // this is the trigger collider attached to the player object.
         {