I made this lithophane box and lightstrip board. 
Requires soldering. 

All the items i used can be found in the links. 

For the lithophane i used https://lithophanemaker.com/ .

Size: 82x82mm | No Border

the lithophanebox is made to pressure fit at 82x82, so make sure you dont press on thinner places of your lithophane.

The led strips are cut, placed on the board, and i soldered the + to + and - to -, so that they are linked together. 

The black wire from the USB C Female goes to 1 negative solder point, since i included each side to be connected you can choose wich side, Solder the Red wire from the USB C Adapter to the Black wire of the Rocker Switch, Solder the Red Wire from the Rocker Switch to the + Solder point on the led strip.  Use a bit of superglue to glue the ledboard on the 2 bars inside the box.

I used 20AWG Speaker wire to connect each solderpoint of the led strip to each other. Since speakerwire is compatible with low voltage and allready has positive and negative marks. 

Be sure to use 5V led strips.

Led Strip: https://shorturl.at/cjf29

USB-C Female Adapter: https://shorturl.at/RtlLk

Rocker Switch: https://www.temu.com/goods.html?_bg_fs=1&goods_id=601100692463009&sku_id=17596891474342&_x_chnl_src=top_banner&_x_big_sale_name=spring&_x_sessn_id=7rpfkk4swa&refer_page_name=bgt_order_detail&refer_page_id=10045_1751662929639_i9t6xqsa2y&refer_page_sn=10045