Select a metal picture frame that is 29-by-42 inches and 2 inches deep. Put the frame together with glass cut to fit. Typically, the glass is held with spring clips that insert from the back and snap into place to press the glass against the frame.
Purchase 145 inches of chase lights. These can vary from holiday lights to rope lights. If you use rope lights, you will need to purchase three 90-degree corners that allow the rope to make the turn; the lighting store salesman can help you choose the necessary accessories.
Drill a hole in the bottom frame close to one corner. This hole is for the wires. Make a second hole near the first one that will fit a small chase-light switch. The second hole may need to be square in shape; if so, use a small rotary tool to cut the correct shape and size to match your switch.
Insert a rubber gasket into the wire hole to prevent electrical wires from chafing on the metal frame. Install the switch so that the switch faces downward
Attach chase light clips to the inside center of the frame using construction adhesive. Attach your end light -- the one furthest from the plug end -- on the bottom side, close to the electrical hole. The lights should run up the side, across the top, down the opposite side and across the bottom to the switch. After the adhesive has dried, press your lights into place.
Cut your chase wire light so that it can easily reach the switch with 1/2 inch of extra wire. Strip off 1/2 inch of the insulation and connect the positive wire to the plus side and the negative wire to the minus side of the switch. Wrap all exposed metal wire with electrical tape so that no metal wire touches the frame.
Turn the frame face down. Measure the inside width and inside height of the frame. Cut 1/4-inch plywood to measure 1/8 inches less than these dimensions so that the frame will fit over the plywood. Most home improvement stores will cut the plywood to size for free. Paint the plywood white on all sides using paint and a foam roller. Allow the paint to dry.
Cut J-molding to the width of the plywood and screw the molding along the bottom edge of the plywood. This is the kind of molding used to hold the bottom of mirrors. Attach two mirror clips facing inward along the left side edge of the plywood. Attach two mirror clips facing upward along the top edge of the plywood.
Position the plywood at eye level -- about 5 feet above the floor -- and ensure that it's level and close to an electrical outlet. Use a stud finder and screw the plywood to the wall studs. Slide the frame over the upward mirror clips so that the frame completely covers the plywood.
Measure the distance from the outlet to the wire hole in the bottom of the frame. Cut your plug-ended wire a few inches longer than your minimum length. Strip off the last 1/2-inch of the wire insulation. Thread the wires through the hole and attach them to the switch, matching the positive wire with the plus side and the negative wire with the minus side. Wrap all exposed metal wire with electrical tape so that no exposed wire touches the metal frame.
Dry mount your posters on foamcore using a framing service. Have the foamcore cut to the size of the posters. Insert the mounted poster into the J-molding and under the two left-side clips. Place the frame over the plywood and turn on the switch. The chase lights should run around the inside of the frame, illuminating the poster.