Prevention is the best approach to handle difficult board members. Make sure that your agency's board member goals are clear and they are able to integrate their vision with the organization. This will decrease the amount of instances when the advice of a board member is counterproductive. If a problem does arise be quick to address it and don't ignore bad behavior. Refusing to act will only make the situation worse.

Direct intervention is the first step to initiate a conversation one-on-one https://theboardmeeting.blog/how-do-you-keep-up-with-trends-in-your-industry/ with the person who is causing trouble. You must be professional and calm, but also direct and state your concerns clearly. It is ideal that the person agrees with you and alter their behavior, however in the event that it doesn't work, you can try making an intervention in the group with the chair and/or someone other board member whom the chair respects highly. You might also review the Values Statement of your organization and/or other documents that govern your organization for language that can be used to define acceptable behavior - for example, respecting people and courtesy.

Another option is to ask the person to quit the board (ideally in a voluntary manner however, if needed you can do it through a vote in confidence). This requires careful preparation and planning prior to the meeting or conversation. For instance, make sure you are aware of the major issues that you want to address and have an organized response in place. Be assertive, yet maintain a polite tone.