are the tail and dash lights controlled by the ignition switch in a 98 GMC sierra 3/4 ton?

My ignition switch has been going bad for a while and I've had to wiggle it to get the dash lights to illuminate. Now the dash lights and radio have quit working all together as well as my tail lights.?  The brake and turn signals still do work however. Does the ignition switch control the dash and tail light illumination?  Head lights work fine, no problem.