Is there any trick to determining wire gauge when you can't see the print on the insulation. My 20 year old kitchen has 15 A outlets on a 20 A breaker and I fear that the wire is 14 guage. How could this happen? Houses were inspected back in the '70s were they not? I can not get to the wire at any other place than inside the outlet box and I can' find any print. Any ideas what I can do to determine if this is 12 or 14 (DOH!).