This post may seem odd, at first glance. And, thankfully, this circumstance does not come up everyday, (literally). But, it is likely that this scenario will present itself more and more, as time passes. And the reason for this is the insurgence of the radical patriarch: the husband and father who claims the final say in all things, ecclesiastical, or familial.
In the case of an abusive husband, (who is or is not a church member), whose wife is a church member, the session (elder board) of the church must take jurisdiction over the case, and intervene, as a greater authority (than those that exist within the family). It is that session's duty to protect this woman, for her good, and Christ's glory.
Some, who would assert the inviolability of the home (or family), might object, claiming that the elders have no right, or jurisdiction here. But this is incorrect: they do indeed have authority in this realm.
It may be necessary, in some cases, to counsel the church wife to remove herself from the man. In more extreme cases, it may be necessary to advise her to divorce him.
It is hoped that none of these situations would ever present themselves; and God is able to save His church from the uttermost--but this is the kind of situation that delineates the differences between godly ecclesiocentricity, and the ungodly form of patriarchalism.