What is the ruling on a wife who contacted her neighbor after her husband swore an oath of divorce upon her if she did so?

The fatwa is that you were divorced from your husband by speaking to your neighbor, whom he swore by divorce that you would not speak to. If this divorce does not complete the three divorces, your husband can take you back during your iddah. Some scholars, like Ibn Taymiyyah, are of the view that the ruling on an oath of divorce that is not intended to effect divorce is the same as the ruling on an oath by Allah: if the oath is broken, the one who swore it must pay an expiation for an oath, and no divorce occurs. Therefore, inform your husband of what happened and advise him to ask trustworthy scholars. Both spouses are advised that the wife should obey in what is good, and the husband should abandon swearing by divorce in the future.