make a monster randomly move throughout an area every 5 seconds

void Movement()
{
  posX = Random.Range(0, 10);
  posY = Random.Range(0, 10);
  posZ = Random.Range(0, 10);
}

IEnumerator MovementLoop()
{
  while (true)
  {
    Movement();
    yield return new WaitForSeconds(5); // wait 5 seconds
  }
}

void Start()
{
  StartCoroutine(MovementLoop());
}