Voluntold is the past tense of voluntell. To "voluntell" someone to volunteer them to do something without having that subject's prior approval. The situation most frequently occurs in situations with large numbers of volunteers who don't have specific duties within the area they have volunteered. The situation also occurs in small group situations in which someone is required to volunteer for a task but nobody raises their hand. They thus become "voluntold" to do the task by the group leader.
I was unable to attend the staff meeting this morning and, as a consequence, I was "voluntold" to take on the responsibility for completing several critical assignments
When a situation that calls for a volunteer arises and somebody forcibly volunteers somebody else without their permission and/or knowledge. You are volunteered, but it is not you volunteering yourself.
I was planning on getting laid tonight, but instead got voluntold by my brother to cook dinner for my family. Of course, I was not told this until I was just about to leave.