Ed, my friend.....regardless of whether your wife is seeing a counselor for issues within herself (that have nothing to do with possible marital difficulties)....OR, she sees him/her due to what she feels are difficulties between the two of you.....Yes, absolutely you should be willing to go along. If the counselor feels this is important and your wife has approached you with this.....I see no fair reason for you to refuse.
One way or the other, Ed, you need to (and should want to) be involved in a situation that is of concern to your wife...and/or your relationship. I can easily predict that should you decide you want no part of this, you will seriously regret this decision. If not now......in the future, please believe me.
If going to an appointment makes you feel uneasy or fearful, rest assured Ed, professionals are trained to help you to be comfortable and will do whatever is necessary to walk you through a session as painlessly as possible.
Whatever your decision, I wish you and your wife the very best of results and a clearer understanding of one another. For the vast majority of individuals/couples....."counseling" can be cathartic and quite beneficial....Good luck, Ed......Peace & Love, Paula