Caller did not leave a message, will have to try and answer the call next time it comes in.
These calls most likely are ESOC/Energy Service Companies attempting to direct-sell electricity through a vendor other than a company your utility provider is buying from. There has been an noticeable increase in telemarketing and door-to-door sales over the last few months. Avoid these companies like the plague, NY enacted legislation requiring that vendors offer customer value in the form of rates and terms that are lower than the utility company is currently providing. The ESOC counter-sued to have the pricing legislation overturned as being unfair -- this action should speak volumes about business practices and intent.
Actively attempt to engage these callers, do not purchase or offer them any usable information just find out who they are and what company they represent. If calls have not been spoofed they are almost certainly hiring temporary reps who can bulk-dial local phone numbers. This would be a convenient workaround for the do-not-call list, a remote/temp rep can later claim no affiliation with a company or telemarketing activity.
A company will need to be mentioned in connection with a sale so find out who the underlying company is and report them.
https://www.ftc.gov/faq/consumer-protection/submit-consumer-complaint-ftc