Often, things are a bit more challenging than they seem at first glance. Mounting bubble lights to a wall requires keeping the lights up straight (heat from the lamp makes the bubble tube bubble) and getting the lights far enough from the wall to stand straight (the lights are tall and wide).

First, I designed a bracket (design and print files available on this site).

This will hold a light up straight.

I used 3M command (velcro like) strips to hold the brackets in place--but they could be fastened with screws if holes were drilled (or designed) in the back of the bracket.

The lights stand upright and bubble with this bracket.

The cord between lights is ugly and will have to be somehow made less noticeable. Also, blue bubble lights don't like to "self start" and have to be "flicked" by hand to get them going--which means blue will probably be pulled from the string.