JModuleHelper/getLayoutPath

From Joomla! Documentation

This method returns the path to the layout file for the module. It checks if there is a layout override in the 'html' folder of the template (See: How to override the output from the Joomla! core). If there is, it returns the path to the override file; otherwise it returns the path to the original layout file. Note that, unlike other JModuleHelper methods, you must include the 'mod_' prefix here. If the module does not exist the path to the layout file will still be returned.