Obviously this is a most distressing situation for you. In the absence of auditory hallucinations, and if you are sure you did
not say anything to anyone, write something in your journal, or other such action, we must consider the possibility that your wife may be able to telepathically understand your thoughts.
You can test this by thinking of something specific, which will catch her attention and something which she will be sure to tell your informants.
I understand how crazy this sounds, but I assure you I have been studying this topic for some time, and like it or not, some people seem to have a gift. Just because we don't understand it and cannot prove it through empirical methods does not mean it is not happening. You may wish to read a book about near death experiences, by Dr. Raymond Moody, called LIFE AFTER LIFE.
Try the test I suggested and I think you will get a clear answer. What you do about it is another issue altogether.
Best of luck, and warmest regards,