keep getting this call, when answered asked to speak to the person who pays the electric bill??
what's up with that?

I keep getting calls from this number several times a day for weeks. no one says anything, I can hear them but they just hang up when we say hello, hello hello .. it says autozone on the caller ID

I have been getting calls for at least a week.  3 or 4 times a day.  At all times of the day.  781 is a MA area code.
I believe they are a company selling electricity.  Seriously, if you have National Grid or some other big electric co. you can choose a smaller co. to supply your power if they have cheaper.  I finally got rid of them when I told them I had Solar Panels and a wind farm.
I'm able to get all this info. because I'm retired and have time on my hands and if this helps, I'm happy about that.