Remodeling an older house and am trying to remove this bathroom light fixture without damaging the wallboard. Rectangular, horizontal fixture, 3 sockets across. seems to be an open-sided metal box with wood trim around the front. Top and bottom slide into the wall cavity between 2- 2x4's. I can only get it to pull out about 1 1/2 inches. No spring tabs that I can feel and no lip on top or bottom. Tried using a putty knife along the edge but no luck. Sockets don't unscrew to allow it to come out and there are no screws around the edges. Anybody have any suggestions? Thanks
no brand name. probably from the 80's