Hundreds of employees at Granite Telecommunications plan to shave their heads Monday for charity. Granite is offering $3,000 for every head or beard shaved, and administrators precdict the fund-raiser will raise close to $1 million. According to the company’s general counsel, Mike Galvin, the idea began when chief executive officer Rob Hale Jr. offered to donate $1,000 to charity if a promoted employee shaved his beard. The employee challenged Hale to double the offer. “Later that day, other people with beards offered to do the same, and Rob accepted the challenge,” Galvin said. “It snowballed to an open invitation to anyone at Granite to shave beards and, if they are wiling, to shave heads to make the same donation.” Hale’s mother, Judy, soon offered another $1,000 for each employee. Funds will be donated to Dana-Farber Cancer Institute, which has been supported by the family since Rob Hale’s father died from pancreatic cancer four years ago. “Dana-Farber did a tremendous job for the Hale family,” Galvin said. Hale family members “have invested a lot of time and effort into supporting’’ their cause.