951-783-3238

This is one of many numbers that call randomly, never the same number more than once.  When you call it back (from a blocked number, of course) it will say, "you have successfully reached the voicemail box.  please leave a message at the tone."  No ID of any kind.  This one purports to be from Riverside, CA, but I've had them come (allegedly) from all over the country, same stupid message.  SCAM!
If you get one of these calls, don't answer.  Call it back (block your number) and just leave random gibberish so they have to listen to it in hopes that someone actually meant to call them back and give them info for their scam.  If enough folks do this, maybe they will stop bothering people because it's not profitable.