How to Call a static page in WordPress

So long as you have a standard page template header in your map-template.php, you can use the Custom Post Template plugin (which essentially allows you use templates on posts in the same way you do with pages).

Update: Perhaps you might be better off using shortcode.

For example;

This is my post content in the editor. And here is a map;

[my-map]

And in functions.php;

function __my_map_shortcode()
{
     // output map
}
add_shortcode( 'my-map', '__my_map_shortcode' );