A component that allows you to subscribe to the Collision Events on a object (even if the main script does not lie on the object with the collider)

CollisionDetector.cs

using UnityEngine;    

//A component that allows you to subscribe to the Collision Events on a object (even if the main script does not lie on the object with the collider)
public class CollisionDetector : MonoBehaviour
{
    public delegate void Coll(Collider collider);
    public event Coll CollisionEnter;
    public event Coll CollisionStay;
    public event Coll CollisionExit;

    void Start()
    {
        if(!TryGetComponent(out Collider coll))
        {
            Debug.LogError($"No collider found on {gameObject.name}");
        }
    }

    private void OnCollisionEnter(Collision collision)
    {
        CollisionEnter(collision.collider);
    }

    private void OnCollisionStay(Collision collision)
    {
        CollisionStay(collision.collider);
    }

    private void OnCollisionExit(Collision collision)
    {
        CollisionExit(collision.collider);
    }
}