RewriteRule ^files/(.+) wp-includes/ms-files.php?file=$1 [L] code example

Example: wordpress .htaccess file code

# BEGIN WordPress

RewriteEngine On
RewriteBase /
RewriteRule ^index\.php$ - [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]

# END WordPress