¿Iniciar/detener el uso compartido de Internet desde un script?

Ligeramente diferente al otro applescript publicado (creo que de mejor manera pero ). Tener opciones a veces puede ayudar.

 tell application "System Preferences"
   activate
   reveal (pane id "com.apple.preferences.sharing")
 end tell

 tell application "System Events"
   tell process "System Preferences"
     try
       click checkbox of row 11 of table 1 of scroll area of group 1 of window "Sharing"

       if checkbox of row 11 of table 1 of scroll area of group 1 of window "Sharing" is equal to 1 then
         repeat until sheet of window 1 exists
           delay 0.5
         end repeat
       end if

       if (sheet of window 1 exists) then
         click button "Start" of sheet of window 1
       end if

       tell application "System Preferences" to quit
       activate (display dialog "Internet Sharing preferences sucessfully flipped")

     on error     
       activate
       display dialog "something went wrong in automation but you are probably in the right menu…"
       return false
     end try
   end tell
 end tell

Modificado uno de los scripts de arriba para activar Compartir Internet en OSX MOJAVE (10.14), funciona:

tell application "System Preferences"
    activate
    reveal (pane id "com.apple.preferences.sharing")
    delay 0.3
    set current pane to pane "com.apple.preferences.sharing"
    delay 0.3
    set localized_window to the localized name of the current pane
    set localized_app to (localized string "System Preferences")
    set localized_ok to {localized string "OK"} -- File sharing
    set localized_start to {localized string "START"} -- Internet sharing
end tell
delay 0.3
tell application "System Events"
    tell process "System Preferences"
        click checkbox 1 of row 7 of table 1 of scroll area 1 of group 1 of window localized_window
        delay 0.2
        select row 8 of table 1 of scroll area 1 of group 1 of window localized_window
        -- change row numbers to the service you want toggled
        if (exists sheet 1 of window localized_window) then
            try
                click button (localized_ok as string) of sheet 1 of window localized_window
            on error
                click button (localized_start as string) of sheet 1 of window localized_window
            end try
        end if
        set sharing_state to the value of item 1 of static text of group 1 of window localized_window
    end tell

    tell application "System Preferences" to quit
    display notification sharing_state with title localized_app
    --  display notification exists since OS 10.9, for older systems use: 
    --  display dialog sharing_state buttons {localized_ok} default button 1 with title localized_app giving up after 1.5
end tell

/usr/bin/defaults write /Library/Preferences/SystemConfiguration/com.apple.nat NAT -dict Enabled -int 0