I wish I had an sword
You get your dish, and you fill with water and then become a fish.
No wish? I wish I had some plutonium. (No, plutonium isn't really dangerously radioactive, neither is uranium.)
It accidentally transmutes to weapons-grade plutonium and spontaneously explodes when you recieve it. (btw, I actually have some depleted uranium in real life. That's why I said it wasn't dangerously radioactive.)
No wish for me to grant.
I wish I was a tree.
You explode due to being an Australian eucalyptus tree during a wildfire. I wish the Powder Toy was 3D.