Good ways to hide money at home?

Put it in a cold return register. There's no heat or forced air coming through it so it will be safe. I have a cold air return in the front, on the bottom by floor, of my shower and I put things in there all the time. It's easy to unscrew and no one would ever know. I also have taken a picture off the wall and open the back of it and put money in it. Once you put the back cover back on you can't tell there's anything there, then just hang it back up. Good luck.