add_filter( \'template_include\', \'wpsites_home_page_template\', 99 );

function wpsites_home_page_template( $template ) {

    if ( is_singular( \'page\' )  ) {
        $new_template = locate_template( array( \'single_page-template.php\' ) );
        if ( \'\' != $new_template ) {
            return $new_template ;
        }
    }

    return $template;
}