Ghost: Calling Form Controllers

gistfile1.php

<?php
/**
 * How to call a form within a function.
 */
function ghost_examples_form_controller() {

  $form = drupal_get_form('ghost_form', 'Drupal\ghost_examples\Form\ExampleForm');
  $output = drupal_render($form);

  return $output;
}

/**
 * Implements hook_menu().
 *
 * Calling your form from a menu callback.
 */
function ghost_examples_menu() {

  $menu = array();
  $menu['my/page/callback'] = array(

    // Your page callback should always be the same.
    'page callback' => 'ghost_form',

    // Your page arguments should start with your Controller, and the method
    // to call.
    'page arguments' => array(
      'Drupal\ghost_examples\Form\ExampleForm',
    ),

  );

  return $menu;
}