As I said in my other post, it'll be considered premeditation for assault and/or other crimes. You're not legally allowed to have a "home defense weapon". You can use things in your house AS weapons, but you can't specifically design something to be a weapon with the intent to hurt someone, intruder or otherwise.
It's similar to how you can't put traps in your house. The reason barbed wire or nails are a bad idea is that it's impossible to explain as other than "it was meant to hurt someone". Just having a bat in your home, or even a gun is a whole different story. Going to the range, baseball, sentimental value- all of that has an alternate purpose that (without a direct confession) could never be dis-proven, so it isn't even considered by any half-decent lawyer.