How do I remove obsolete Network entries from Network Connection Applet

I see that I can delete networks that my machine "remembers" from nm-applet by clicking on the wireless icon in the panel and selecting "edit connections" -> "wireless". However, sometimes I click on the wrong wireless connection by accident in the dropdown list. If the connection is secure, the machine of course never successfully connects, but somehow it still seems to memorize the ESSID. Whenever I'm in range of that wireless, it now tries to connect.

Worse, if not connected to any other network, it repeatedly prompts me to connect to this network. If left unattended, I may find dozens of copies of the window prompting me to log in to this mistaken network. There must be a file somewhere that records this connection ID, but I cannot find it. The only connections appearing in the "edit connections" I mention above are those to which I've actually connected. How do I find the file and delete the line corresponding to the offending "memorized" network?

EDIT I seek a solution to remove those networks from whatever list they get added to when I first select them. It appears this behavior is a bug in the network manager(?)

have you tried to delete the files in the directory /etc/NetworkManager/system-connections/ ?

You should have 1 file for every net you have tried to connect, open a terminal and use the commands:

sudo ls -l /etc/NetworkManager/system-connections/

To list all the files, after you have found the network that you want to delete, remove them with the command:

sudo rm /etc/NetworkManager/system-connections/NETWORK_NAME

You can delete connections using nmcli con delete (CONNECTION_NAME)

To delete all connection never used ( no root needed )

nmcli --fields UUID,TIMESTAMP-REAL con show | grep never |  awk '{print $1}' | while read line; do nmcli con delete uuid  $line;    done

If your major problem are those annoying prompts asking you to log in to a network, then whenever you are not using Wireless, you can just Disable Wireless by clicking the Enable Wireless entry in your Network Indicator Menu.