A way to retrieve and cache singleton/manage type monobehaviours

CachedReference.cs

using UnityEngine;
using UnityEngine.Assertions;

public static class CachedReference<T> where T : MonoBehaviour
{
    private static T cachedReference;

    /// <summary> Returns null when it cannot find the type  </summary>
    public static T FindCachedObject(bool includeInactive = true)
    {
        if (cachedReference == null)
        {
            cachedReference = Object.FindObjectOfType<T>(includeInactive);
        }
        Assert.IsTrue(cachedReference != null, $"Couldn't find an instance of type {typeof(T).Name} in the currently loaded scenes. Make sure you have attached {typeof(T).Name} in the scene somewhere");
        return cachedReference;
    }

    public static bool ReferenceExists() => cachedReference != null;
}