Cell phones have become a phenomenon. Just about everyone has one, but not everyone knows calls can be traced easily by people other than law enforcement. Because of the new demand for spyware and phone bugs, it has become easier to detect phone calls.
Keep a log of all private calls, include date and time. Submit the log to your carrier and they can trace the calls and give you the number.
Mysterious calls can be traced via online phonebooks. Most of these sites have number reversal that allows you to enter the number, and then it will give you the caller's information.
If all else fails, call the number back to see if you get an answer.
All calls are traced by your provider. Contact them to get a copy of all your calls. Once you have finished tracking your calls, they should be reported to law enforcement officers who will make a file.
To trace a call, you can use pay sites. For a fee, you can supply a phone number and the site will collect all information attached with this number, such as address, name and cell phone carrier.