Mac OS-X Showing Existing Wifi Passwords in Keychain

Show the WIFI Password

Go to your applications folder
Click on the Utilities folder
Click on the “Keychain Access” App
On the left-hand side, highlight the “System” keychain
Select “Passwords” under the category
Double-click on the Airport network password you want to remember
Select the “Show password” checkbox
Enter your administrator username and password (you may have to do this twice)
See the password in the “show password” field.