I'm getting the same thing. Caller ID just shows "S" as the name and the phone number (without the area code). They're calling with two different numbers. One is 848-6540, the other is 848-6552. Both with the same name.. "S".
I've checked with dexonline.com to backtrack the caller.. they're listed as a WA #'s but no other information is given. Same as everyone here, they call several times a day for several days a week and leave no messages. I work nights and "try" to sleep days (hard with a one yr old baby) and this is getting quite ridiculous. My wife's thinking it may be a collection agency, if it is... it's a sure-fire way of killing any type of collaboration or cooperation. If it's a bugged system..wow.. wild to think computer viruses moving into the telephone systems. I know cell phones are able to contract PC-like viruses, didn't know if landline systems could either.. if it is. :/