EnemyPatrol.cs

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

public class EnemyPatrol : MonoBehaviour
{
    public bool moveRight;
    public static float speed;
    public GameObject Ghost;

    void Start()
    {
         speed = (Random.Range(1f, 1.5f));
         Rigidbody2D rigidbody = GetComponent<Rigidbody2D>();
        rigidbody.velocity = transform.right * speed;
    }

    void Update()
    {
        if (moveRight)
        {
            transform.Translate(2 * Time.deltaTime * speed, 0, 0);
            transform.localScale =new Vector3(-1, 1,1);
        }

        if (moveRight == false)
        {

            transform.Translate(2 * Time.deltaTime * -(speed*2), 0, 0);
            transform.localScale = new Vector3(1, 1,1);

        }
    }

    void OnTriggerEnter2D(Collider2D other) //Pickups 
    {
        if (other.gameObject.CompareTag("turn")) //If you got the key
        {
            moveRight = false;
        }

        if (other.gameObject.CompareTag("turnback")) //go right
        {
            moveRight = true;
        }


    }
}