Caller ID says "Billerica MA". They leave no message.
I call back after hours (using *67 to block my number). Their outgoing message is, "Thank you for calling the Epilepsy Foundation donation center. If you know your party's extension, you may dial it at any time. For a dial by name directory, please, press 2. If you would like to schedule a pick up or for any other inquiries, please, press 0. Thank you."
In the past they have wanted old clothing / furniture / stuff. They pick it up and sell it at a thrift store. The resulting money goes to their foundation. I believe the caller is what their message says they are.
However, I can't say I appreciate them spoofing their caller ID.