A:Answer If you don't have a good option for hiding the wires you have a couple options:
Use the batteries Lithium batteries shoudl give you a year or so before replacement
Drill a hole into your home and use something like Raceway conduit to hide the wires going a plugins or the like to make power available.
I would suggest simply using batteries instead though, as they are easy to replace, last a while, and warn you when they are low.