There are at least two I can think of off hand;
1. Canadian Red Cross is always looking for volunteers. Not all have an interest in fundraising but if that is an area of interest, there are opportunities to help. There is a big (annual) campaign in early August and I am certain the local Branch would need committee members for it. Contact the local Branch just behind Milton Mall. Or PM me and I can pass along name and contact information.
www.redcross.ca
2. While I work for the Red Cross (Provincial Office), I have been active with the Milton Lion's Club since moving to Milton 3 years ago. We are always looking for support at events. I am the Lion's Club lead for the Lion's Wish (formerly Leslie Wells) Softball Tournament. This is a fun and excellent fundraiser that is in its 15th year. Money raised is used to help individuals, families and organizations in Milton. Some of the proceeds from last year's tournament have gone to the Hospital, families with children facing cancer, a local Olympic hopeful, Schools, etc. Helping at this event would also be a great opportunity for you and the tournament organizers would likely want help on other fundraising ideas for that weekend. Again PM if interested and I can make introductions.