Well in MA it's the case you have to have specific S license to do security. At least recent experience in in one town anyway.

In RI and CT you have to have a low voltage license and I do not believe that having an EC covers it. In CT there are actually 2 different licenses a T1 if you are just a worker, but you need a T2 to pull low voltage permit and again I do not believe that having an EC license covers that in CT.