Just got a call today also. Caller ID said "Castor C." Allowed answering machine to take the call. They hung up without leaving a message. This was around 6:15 p.m. EST.
After checking, this number belongs to an insurance agent in Texas. I live in N.E. Ohio, so what gives? Here is the link that shows this number for Curtis R. Caster. (Note: I misspelled Caster as Castor. Sorry)