Should you confront the person your spouse is having an emotional affair with?

Yes you do before it's to late and before it gets to bad. The worst thing that a person can do is to know that their spouse is falling for another person. I don't know the situation that your having with your spouse but take my words for it from my own experience and nightmares learning that the man I married didn't have no problem giving his heart to another woman.
If the two of you have children, think about your children and what could happen if you don't stop this now. If you still love your spouse or let say you want to give it another chance, think if you can have the trust you used to have.