"NullReferenceException: Object reference not set to an instance of an object" When Raycast hits and tries select a designated object

This script is acting strange... I have tried solutions from other answers but they don't seem to work at all. I have a ray that constantly checks for GameObjects with the layer "Interactable". The ray has no difficulty identifying the objects, but when it tries to selected it and store it in a variable for further purposes, it returns this error: "NullReferenceException: Object reference not set to an instance of an object"

Here's the script:

 #pragma strict
 
 var cam : Transform;
 var layerMask : LayerMask;

 function Update () {
 
     var ray = new Ray(cam.position, cam.forward);
     var hit : RaycastHit;
 
     if(Physics.Raycast(cam.transform.position, cam.forward, 100, layerMask))
     {
         var selectedObject : GameObject = hit.transform.gameObject;
         Debug.Log("You hit something");
         
     }
 }

I've also tried this but it didn't work either:

var selectedObject : GameObject = hit.collider.gameObject;

What is wrong? Thanks!