In Plain Sight - -Gold Coin Security

There are really a lot of those when you think about them.
For example at most joke or magic stores they sell those fake vomit looking things. Place them on your bathroom floor and put all your coins inside those.
Lay out your coins on a table in room and close the door. Hang a sign on that door saying Quaranteened, contagious type of Leprosy. Place a dummy in a chair at that table with ketchup all over the head in case a criminal opens the door.
Instead of a safe purchase a coffin. Place in a room, put a dummy in there, note saying Aunt Mary, may she rest in peace after that long bout of Tsu Tsu Gamushi. Then place all your coins under that dummy.

Its illegal to set a booby trap. I don't know about inside the house. I found this out while contemplating solutions to the loss of more than a couple hood ornaments and was thinking about welding a few well placed razor blades to it.