This can definitely be done. Simple program actually, use the smart plug to do the work. Use a wall adapter to power the Arduino from the smart plug. Program it so that when it comes on, it simply moves a servo down and back up again. Look at the sweep example, that's got all you need. You may need to change the angles it runs to from 0-180 to something else, but that should be pretty self evident what to do from the code and comments. And you would want to move the code from loop up into setup so it only runs once. You'd have nothing in the loop function
I have to admit, when I came into this thread I was hoping that we were talking about some sort of attack Roomba that came on when the alarm went off and attacked whoever was coming in. :)
Thanks for the reply, very useful! I will definitely give this a shot.
Hehe, maybe that's the next step - to attack the burglars!