Custom template router for WordPress.

custom-template-router.php

<?php
add_action('template_redirect', 'twr_custom_template_router', 1);

if( ! function_exists( 'twr_custom_template_router' ) ) {
    /**
     * Routes predefined list of pages to custom template_redirect
     */
    function twr_custom_template_router() {

        $custom_templates_bucket = array( 'schoolsguide', 'school' );

        $request_uri    = $_SERVER['REQUEST_URI'];
        $url_segments   = explode( '/', $request_uri );

        foreach( $custom_templates_bucket as $custom_template ) {

            $index = array_search( $custom_template, $url_segments );

            if( $index ) {
                $template_name = $url_segments[ $index ];
                $template_path = get_stylesheet_directory() . '/custom-templates/' . $template_name . '.php';
                twr_include_wordpress_template( $template_path );
            }
        }
    }
}

if( ! function_exists( 'twr_include_wordpress_template' ) ) {
    /**
     * Renders template file
     */
    function twr_include_wordpress_template( $template_path ) {

        if( ! file_exists( $template_path ) )
            return;

        global $wp_query;
        if ( $wp_query->is_404 )
            $wp_query->is_404 = false;

        header("HTTP/1.1 200 OK");
        include( $template_path );
        exit;
    }
}