I've been contacted by others who want to verify a DX with me, but I was not operating at that time! It appears that someone made several contacts using my callsign for a short window of time one day.
I've been keeping my ears open, but haven't seen it myself, and the only information those who contacted me have are the dates, times, and frequencies of the contacts.
What should I do once I find my call being used by someone else? Is there any reporting I should perform to the FCC?
Is there anything else I can do besides listening to catch them? If I do hear them, is there a method I can use to at least narrow down their location?