You can't be 'found guilty' in a civil action.
Your name can only have come to the attention of the solicitor if either
(a) a person involved in an accident gave your name and address instead of his own ; or
(b) far more likely, the DVLA has been asked to disclose the registered owner of a vehicle with your car's number plate.
In the case of (b), that could have occurred because
(i) the other driver involved in the accident wrote the number down incorrectly ; or
(ii) the solicitor or the DVLA have made a typo at some stage ; or
(iii) your car's number plates have been cloned and a vehicle carrying your car's registration was actually involved in an accident (even though it wasn't your car).
Wait until you receive something in writing. Once you've got the details of the alleged accident, try to work out whether you can prove that you were somewhere else at the time (e.g. because you were giving a speech to several hundred people, or simply clocked in at work). If you think it's possible that your number plates have been cloned, inform the police and get a crime reference number (so that you can provide it to the solicitor and, if necessary, to a court). Write to your insurer to tell them that a false claim is being made against you. Then wait to see what happens next.