Redirect single-ctp.php to homepage

snippet.php

<?php

// How to disable the single view for a custom post type
// see https://wordpress.stackexchange.com/questions/128636/how-to-disable-the-single-view-for-a-custom-post-type

add_action( 'template_redirect', 'wpse_128636_redirect_post' );

function wpse_128636_redirect_post() {
  $queried_post_type = get_query_var('post_type');
  if ( is_single() && 'my_post_type_name' ==  $queried_post_type ) {
    wp_redirect( home_url(), 301 );
    exit;
  }
}
?>

https://wordpress.stackexchange.com/questions/128636/how-to-disable-the-single-view-for-a-custom-post-type