How do I handle a long gap on my résumé? after 10 years as an electrician's helper

I took time out to care for a family member after working as an electrician's helper. I have read a lot of threads here and could not find my exact situation. I am not sure how much to explain. Did anyone get past it?

I listed the volunteering and course under the same dates and kept the explanation to a sentence in the cover letter.