It's not fishy.  If you applied for a job with a company who does background checks, this is the company they use (Accurate Background, Inc.).  If they called you it is because they need additional information to complete the background and the company you applied with has given them your contact information so they don't have to call.  Take the call and they would tell you what company has requested the report on you.  Not only that, you would have already signed an authorization stating a background would be done on you and it mentions the company name anyway.
Or, if you'd rather, just ignore the call and when the background can't be done and you don't get hired, you can just look somewhere else.