I am pretty sure that the JW virus does not "catch" just by attending a hall, even if it brings back yukky feelings. Minimus, I don't think you will be in any spiritual danger by attending, and it will send a nice message of support to your wife.
Besides, returning after being away for a while can provide a refreshing perspective. I promise your wife will see the hall in an entirely new light!
I really like what rabbit said:
Recently, I attended a family Christmas party with my new wife, why ? I don't believe in it and never will. I went with her -- for her. It was important to her, so it was important to me. Some of her relatives, knowing I had been a Witness were very surprised and told me they were glad I came even tho' I did not celebrate it. They asked -- why? I said, "I love my wife..."
I pick and chose when to support my JW hubby for the same reasons. Of course, he cannot reciprocate in kind without being doused with extreme guilt. THANKS WT FOR NOTHING.