//* Shorcode para aplicar estilo a la caja de post invitado
add_filter( 'the_content', 'shortcode_unautop', 100 );
add_shortcode( 'guest_post_box', 'guest_posts_shortcode');
function guest_posts_shortcode( $atts, $content = null ){
	$output = '';

	if ( !is_home() ) {

		$output = '<div class="guest-posts-box">';
		$output .= do_shortcode( $content );
		$output .= '</div>';
	}

	return $output;
}

// Elimina las etiquetas de párrafo vacías de inicio y fin de los shortcodes
add_filter( 'the_content', 'shortcode_empty_paragraph_fix' );
function shortcode_empty_paragraph_fix( $content ) {
    // define your shortcodes to filter, '' filters all shortcodes
    $shortcodes = array('guest_post_box' );

    foreach ( $shortcodes as $shortcode ) {

        $array = array (
            '<p>[' . $shortcode => '[' .$shortcode,
            '<p>[/' . $shortcode => '[/' .$shortcode,
            $shortcode . ']</p>' => $shortcode . ']',
            $shortcode . ']<br />' => $shortcode . ']'
        );

        $content = strtr( $content, $array );
    }

    return $content;
}