Well, it's a really tough situation. If this has happened, you need to focus on your relationship with your wife. Maybe you two could seek professional counseling. A counselor can help you both dig deeper into what led to this, whether there were underlying issues in your marriage. And about the person who seduced, stay away from any form of retaliation. It won't solve anything.
This is a complex and distressing situation. In such a case, communication is key. You have to communicate with your wife about your feelings, fears, and concerns. Try to understand if there were any problems in your marriage that might have made her vulnerable to this so - called seduction. As for the other person, you can try to set boundaries. For example, if it's someone in your social circle, make it clear that their behavior is unacceptable. But above all, focus on rebuilding the trust and connection in your marriage.
First, you should have an open and honest conversation with your wife. Find out her side of the story and how she feels about the situation. Then, it might be a good idea to confront the person who you think seduced your wife in a calm and collected manner, but be careful not to do anything illegal or unethical.