I was hoping I wouldn't have to spell it out. I'm really talking about where someone hears you are into bitcoin so they turn up at your house, force their way in and put a gun in your mouth. I didn't want to get so graphic, but I think we as a community should develop safeguards for this.
these people might not be very smart, but they might be thugs
In that case, they have no idea how much Bitcoin you have, they have no idea what your Bitcoin addresses are, so just hand over a decoy wallet containing a small amount of BTC. They will have no way to know if you have more than that.
But if someone kidnapped someone who they knew had a lot of bitcoin that will not work. Maybe you told your wife you have a lot and she told her friend and someone else found out. This is a possibility for some people.