I am not sure if this is still the case, but three years ago I was able to get an afternoon-only ticket that was made available only to people attending conventions and meetings on property. However, if my memory serves me correctly, the ticket was only available for the actual convention attendee--not the attendee's family.
I am almost certain that such a program still exits. However, I believe the tickets are only available from the event sponsor--i.e. you can not walk up to a ticket booth and say you're there for a conference and want a half-day ticket. If you husband has a meeting or convention on Disney propoerty, you should have your husband ask his event coordinator for information.