The picture is an IKEA picture called ''ERIKSLUND'' in a black frame.
This picture was good for this project because it had some free space inside between the backside and the frontside of the glass.
Step 1: All What You Need
Shrinking hose in different sizes, double side adhesive tape, hot melt gun and a few screws.
Step 2: Remove the Backside
Step 3: Make Holes for the Switch and the Power-Cable
The Hole for the Switch can be may at a lower Edge in the Side.
A Good Place for the Hole for the Power Cable is at the Downside in the Near of The Switch-Hole.
Step 4: Solder a Piece of Wire to the LED-Bar
Make 2 Pieces of the Shrinking Hose that are approximatly 3cm Long and Put it over the Wires. Then you can Solder the Wires from the LED-Bar each with one Wire from the 2 Wire-Cable. Then Put the Shrinking Hose Pieces over the Soldered Area and Shrink it with the Flame of a Lighter.
Step 5: Attach the LED-Bar in the Frame
Cut 3 or 4 Pieces from the Tape Roll and attach the Bar with this into the Frame at the Top-Side.
Step 6: Attach the Cable
Step 7: Attach and Connect the Switch
Solder the Second Pole of the LED-Bar to the middle Brad of the Switch and Isolate it with Shrinking Hose in a Bigger Size, the Second Pole of the Power Supply you can Solder to One of the Other 2 Brads of the Switch, Doesn't Matter, Isolate this Brad too and Attach the Switch with Hot-Glue.
Step 8: Light Test
P.S. This is an IKEA Light Bar called ''DIODER'' But i Buyed a Single Bar.
Step 9: Reattach the Backside
I used Cross-Drive Screws that are 20mm Long and had a Diameter of 2,5mm.
Step 10: Finish!
The Power Supply is Always Powered, Because in Standby the Power Supply consumed only 20mA