I agree with wobbly that concealment is the key. Over the years I have had the opportunity to get rather creative with my customer's concealment needs. One of my favorites is a false bottom in a drawer, which will drop down after the drawer is opened and a small latch is released. It's simple, cheap to make and almost instantly accessible.
One of my ideas is to go to a used home supply store (like a
Habitat For Humanity "Re-Store") and buy an small, 12x14 accessory breaker box. Throw away the box and mount the modified cover flush on the wall. Put it
behind the walk-in closet door, so that it looks like a standard electrical service point.
However the door hides access to the 15" wide space inside the wall. That space between the studs can conceal a lot of things. And it can be placed high enough on the wall to discourage young, exploring children.
Even if a thief spent an hour inside your home, no one is going to take the time to check your breaker panel. Generic gray breaker panel covers are simply too common, too benign to stand out.