When posting in Facebook how do I add my location by default?
When I create a new post in Facebook I have to manually add my street address. I'd like it to auto detect like Google Plus does. Is there a setting for this?
There is no setting to currently do this. I would imagine that your hometown needs to be "realized" via search (https://www.facebook.com/search/results.php). So if it's not there you would not be able to detect in the profile settings.
Consider creating a new location (https://www.facebook.com/help/?faq=175921872462772) then you should be able to use it as your hometown.