and see if I can get the wife on board.
I gave up on that, and just told her what I'm planning, for the alarm.
I'll try again after it's installed.
All you have to do is make it look like you're working hard. My wife doesn't question anything I do when I have a belt full of tools. It helps that I usually give her a really long boring complex answer if she does ask, and she loses interest as soon as I start telling her.
However, you should always remember that if she does call you out on something that you can always justify the cost of anything by calling it a hobby. What kind of cruel spouse wouldn't want you to have a hobby?