If the glass in installed into a wood frame an LED strip can run around the frame behind the glass. This will give it a nice even light.

Do you know sellers of box frames? Thank you for the idea.

Without seeing the window and where you plan to hang it, it's hard to say. A carpenter would make a simple frame to its exact size. Are you handy? Do you have a picture and size of the window so people could give you more advise?

It will be in a hallway inside the house, I plan to put a back lighting, and use it as a night light.

Picture? If it's square or rectangular ask a carpenter to build a "light box" for it. If it's round it's a bit more complicated. If small and can sit on a stand table you could put a small lamp behind it. They make stands that would be OK for that. If it's large you might have to hang it from the wall in front of a narrow shelf with small candle type light behind it. But you will see the concentrated light source unless it's lit evenly from behind. All depends how large and how much money you want to invest in this application.

Thank you. Bought a 22 x 22 frame to fit the stained glass I bought here at Houzz, and will either have a strip LED as one of you suggested or a small fluorescent as back light. Will post result once this project is completed.

How did it turn out? Please share some photos.
Thanks!