Here's an alternate way of looking at things. Right now you're very focused on yourself, your plight and how your wife might turn you in to the elders. You're in self-defense mode. What about your wife's viewpoint? What about approaching her honestly instead of hiding your lack of belief? She won't be happy, but maybe she will respect you more for being straightforward. Remember that men are about 10x more transparent to women than they think they are, so she probably already suspects/knows your feelings and just wishes you would explain yourself.
Many posters here have gone way overboard and tried to share TTATT with their f&f, and that doesn't end well, but if you simply tell her that it's not the truth for you anymore, that you have your reasons, and that you don't want to impede her own practicing of the religion, then you're placing the onus of the reaction on her. It becomes up to her whether she will have a reasonable reaction or she'll freak out. Whereas you are simply delaying what is likely an inevitable freak-out if you just wait for her to finally say something one day when you least expect it. And if she doesn't ever say anything, then you have it hanging over your head the rest of your married life.
Some ex-JWs have gotten lucky like Phizzy, whose wife apparently wasn't really that into the religion either, but if your wife is zealous then you're in for angst no matter what. Might as well take it like a man.