WPA is WiFi Protected Access - it's the most common method of encryption used to secure a wireless network. If you have a laptop or smartphone and you're trying to connect to a WiFi network, you'll usually need to enter a WPA key (or password) in order to connect to it.
In the live-action adaptations by Sir Peter Jackson, Sauron is portrayed by Benedict Cumberbatch in The Hobbit trilogy (who also portrays Smaug in the same trilogy) and was played by Sala Baker and voiced by Alan Howard in The Lord of the Rings trilogy.
The actor will have a recurring role on the series, and while it isn't clear how many episodes he will star in, Mora will have a connection to the main character Brian Finch, played by Jake McDorman. Take a look at the official synopsis for the Limitless TV series below.