A flickering light behavior for unity.

Flicker.cs

using UnityEngine;
using System.Collections;

public class FlickerBehavior : MonoBehaviour {

	// the (comparatively) steady light phase
	public float minLightMs =   500;
	public float maxLightMs =  5000;

	// dark part of the flicker phase:
	public float minDarkMs  =    25;
	public float maxDarkMs  =    50;

	// the time between flickers in the dark phase:
	public float minFlickMs  =    25;
	public float maxFlickMs  =    50;

	// number of times to flicker during the dark phase:
	public int minFlicks    =     1;
	public int maxFlicks    =     3;

	// internal reference to the light component
	private Light _light;

	void Start () {
		_light = GetComponent<Light>();
		StartCoroutine("Flicker");
	}
	
	IEnumerator Flicker () {
		while (true) {
			// steady light period
			_light.enabled = true;
			yield return new WaitForSeconds(Random.Range(minLightMs, maxLightMs)/1000f);
			// flickering light period
			for (int i = 0; i < Random.Range (minFlicks, maxFlicks); i++) {
				_light.enabled = false;
				yield return new WaitForSeconds(Random.Range(minDarkMs, maxDarkMs)/1000f);
				_light.enabled = true;
				yield return new WaitForSeconds(Random.Range(minFlickMs, maxFlickMs)/1000f);
			}
		}
	}
}