What Dilligaf said, garage door opener is the quickest & easiest way (and safest)
On the unit itself there are two low voltage terminal screws to allow you to wire a push button rather than using the remote, all you would need to get the board to do is operate a closed LV circuit, simple.
One press gets it closing, press again & it reverses the motor for you, you don`t even have to get involved with the mains side of things (230v) which you shouldn't be touching anyhow.
You could even have a camera to ensure you squash said intruder.
PM me if you have any questions, i am an English, New Zealand & Australian (qualified/licensed) electrician & professional nerd.