STAMFORD — The Exchange Club Parenting Skills Center wants to dispel a popular myth: that childhood abuse and neglect isn’t a big issue in our community. “It’s right here,” the organization’s executive director Donna Miller said, “and this is Fairfield County.” Nationwide, the problem is staggering. More children died last year at the hands of their caretakers than from childhood cancer, Miller said. It’s the biggest health crisis facing children, with 3.3 million reports of abuse each year across the country, involving up to 6 million children, according to the organization.