Can Internet sharing be configured to be a bridge/switch rather than a separate NAT/router? I'd like to use my wired-ethernet desktop mac as a wifi bridge so that everything that connects to it over wi-fi can see and be seen by everything else on the LAN.

There's clearly no way to do this in the GUI, but I was wondering if there is some way to do it in Terminal.

I'm looking for a solution for El Capitan, but if you have a solution for some other version, that would be acceptable, too.
I saw this link, but instructions are outdated and does not work on El Capitan
http://www.notadiscussion.com/2014/01/how-to-make-real-network-bridge-with.html

Trying to find a solution myself for El Capitan