I've been accepted as a volunteer (actually a trainee volunteer) to man a phone line for the Anxiety Alliance* who give support to people suffering from panic attacks and anti-depressant withdrawal and the like. This would just be for four hours a week. Quite intensive training and then a long probation period, so plenty of time for me to make a mess of it.
*ETA Awful website isn't it? I see they say their helpline is only open 10am-4pm, but they have asked me if I can work evenings, so I wonder if they are trying to expand their coverage.