QuakeLightFlicker.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class QuakeLightFlicker : MonoBehaviour
{
    public float maxLightIntensity = 2f;
    public string flickerString = "mmamammmmammamamaaamammma";

    public Light light;
    int index = 0;
    float defaultInt = 1;
    public GameObject optionalToggleObject;
    char[] chars;

    // Start is called before the first frame update
    void Start()
    {
        light = GetComponent<Light>();

        defaultInt = light.intensity;

        StartCoroutine(Flicker());

        chars = flickerString.ToCharArray();
    }

    IEnumerator Flicker()
    {
        while (true)
        {
            yield return new WaitForSeconds(0.1f);
            if (light)
            {
                int charIndex = (int)chars[index] % 32;
                float value = ((float)charIndex / 32f) * maxLightIntensity;
                light.intensity = value;

                if (flickerString.Substring(index, 1) == "a")
                {
                    if (optionalToggleObject)
                        optionalToggleObject.SetActive(false);
                }
                else
                {
                    //light.intensity = 0.1f;
                    if (optionalToggleObject)
                        optionalToggleObject.SetActive(true);
                }

                index = (index + 1) % flickerString.Length;
            }
        }
    }
}