The word plug can mean two very different things:
- something that blocks a pipe or other conduit carrying fluid, etc.
- Context is typically plumbing or piping.
- something on the edge of cable that connects it to a socket.
- Context is typically electrical.
Plain non-phrasal plug will typically imply something to do with plumbing or pipes.
The drain is plugged with hair.
Plug in, or plug up in some cases, will typically imply an electrical context.
The power cord is plugged in the wall.
Plugged up sometimes means plug in, especially if we're talking about a job or setup process with connecting cords to sockets, but it can also refer to something being clogged, so context is important for plug up.
I plugged up all the cords. What's next (setup or job context)
The bathtub is plugged up so no water is getting out.
Plugged out does not mean a cord is disconnected from an outlet. The best it could mean is that there's some blockage in a pipe outside, but even then it's somewhat awkward.
Also none of these use the hyphen.