How do I Make a custom post type get a custom post template in a plugin

function get_custom_post_type_template($single_template) {
     global $post;

     if ($post->post_type == 'events') {
          $single_template = dirname( __FILE__ ) . '/single-event.php';
     }
     return $single_template;
}
add_filter( 'single_template', 'get_custom_post_type_template' );

Source

Or you could use:

add_filter( 'template_include', 'single_event_template', 99 );

function single_event_template( $template ) {

    if ( is_singular('event') ) {
        $new_template = locate_template( array( 'single-event.php' ) );
        if ( '' != $new_template ) {
            return $new_template ;
        }
    }

    return $template;
}

Source

Or you could use locate_template