Location of Wifi SSID configs and how to make a hotspot in Ubuntu 14.04

What is the location of wifi ssid config in Ubuntu 14.04. Also, making a wifi connection as Hotspot does not work. I am unable to make a hotspot in Ubuntu 14.04 via UI. One of the reasons that I found was that mode is set to infrastructure in the hotspot config and I need to change it. I tried locating the file in /etc/network/interfaces from online search but that configuration is not something that I am looking for.