Toddler discipline for an extremely stubborn 2 year old?

[idknemore]

My son is 22 months old and full of energy. He is extremely stubborn and determined to do what he wants. I am having a horrible time trying to teach him to listen. He doesn't speak, but he does understand what you're saying. He knows what no, stop, get down, and many other small commands mean. There are several things in my home that I can't keep him out or away from. My home is as baby-proofed as it can possibly be. I am constantly getting on to him about certain things, like climbing or turning on the air conditioner (it's a small window unit in the bedroom). I have tried spanking, distracting, time-outs, and the corner. None of these things seem to stop him. As soon as I let him out of the corner or stop playing with him to go take care of a chore he goes right back to what he was doing that caused him to be punished. I'm at a loss for what to do because nothing seems effective in deterring him from common misbehavior. Another huge problem is screaming. He makes this high pitched scream and won't stop. There's nothing instigating the screaming. In fact he tends to do it most often when we're paying attention to him, whether it's talking or making silly faces. I need help from parents that have had difficult toddlers. I've read the parenting articles and tried the common tips that I'm sure many of you are thinking right now. I need something different, or a new approach to a previous form of discipline. I can't take my eyes of my son because as soon as I leave the room he's going to get into something and get hurt. Please those of you that have been through this or are going through this horrible stage help me out!