GhostMover.cs

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

[RequireComponent(typeof(Rigidbody))]
public class GhostMover : MonoBehaviour {

    public Vector3 nextPlaceToGo;
    public float timerSeconds = 1;
    private float timePassed;
    bool chasing = false;
    public float speed = 2f;

    public int hitPoints = 1;

    public void LaserHit()
    {
        Debug.Log ("I've been hit by a lazer");
        hitPoints--;
        if (hitPoints <= 0) {
            GameObject.Destroy (gameObject);
        }
    }

    void Start() {
        GetComponent<Rigidbody> ().useGravity = false;

    }

    GameObject lookLine;// <-- used to draw math. get Lines.cs from // http://pastebin.com/8m69iTut

    private float killDistance = 1.5f;

    void FixedUpdate () {
        float distance = Vector3.Distance( transform.position, GameObject.FindWithTag("Player").transform.position);
        //Debug.Log (distance);
        if ( distance <= killDistance)
            {
                Application.LoadLevel(Application.loadedLevel);
            }

        timePassed += Time.deltaTime;
        if (timePassed >= timerSeconds) {
            if (!chasing) {
                Vector3 randomOnPlane = new Vector3 (
                    Random.Range(-1f,1f), 0, Random.Range(-1f,1f));
                nextPlaceToGo = transform.position + randomOnPlane.normalized;
            }
            timePassed = 0;
        }
        Vector3 actualDirection = nextPlaceToGo - transform.position;
        GetComponent<Rigidbody> ().velocity = actualDirection.normalized * speed;
        transform.rotation = Quaternion.LookRotation (actualDirection.normalized);
        Ray ray = new Ray (transform.position, actualDirection);
        // this will draw lines. get Lines.cs from http://pastebin.com/8m69iTut
        Lines.Make (ref lookLine, transform.position, transform.position + ray.direction);
        RaycastHit hit = new RaycastHit ();
        if (Physics.Raycast (ray, out hit)) {
            if (hit.collider.tag == "Player") {
                Debug.Log ("SAW PLAYER!");
                //timePassed = 0;
                nextPlaceToGo = hit.collider.transform.position;
                chasing = true;
//              transform.LookAt (hit.collider.transform.position);
//              GetComponent<Rigidbody> ().angularVelocity = new Vector3();
            } else {
                chasing = false;
            }
        }

    }
}