<< 8. get an electric pest deterrent - emits a tone that they don't like and also works against insects. >>
They don't work. In school, we tested a few of these and they are not effective at all. We used el cheapo ones from 12.99 to the ones in the commercial for 70 bucks. If you watch the commercials, they don't put mice near the devices to demonstrate what the effects are. If for some reason they do repel the lil critter, they will more likely run to another part of your place where they can avoid the tone.
If you do decide to try this route, get one with a satisfaction guarantee so you can return it if it doesn't work for you.