want to find out who is this caller

After getting several hang-ups and no real message from this number, I answered it -- they are raising money for Special Olympics.

I suspect this is a boiler-room call center in Woburn, MA, that functions as paid fundraisers.  They had my name and previous activity with the charity in question.  The law lets them use the phone in that way, but it is the same high-pressure telemarketing technique we all know and love.