gistfile1.txt

function contact_form_module_setup() {
  get_template_part( 'includes/builder/module/ContactForm' ); // require the new module file
  remove_shortcode( 'et_pb_contact_form' ); // remove the original module shortcode
  add_shortcode( 'et_pb_contact_form', array( new Cu_ET_Builder_Module_Contact_Form(), '_shortcode_callback' ) ); // add the new module shortcode
}

add_action( 'et_builder_ready', 'contact_form_module_setup' ); // hook with the et_builder_ready filter