I don't know much about the subject and am just not really worrying about electromagnetic radiation that I can't control, such as cell towers.. However, I do think that it's worth being aware of on the smaller scale.
I have a clock that communicates with an sensor outside to report indoor and outdoor temps. Originally, I set up the clock on my nightstand and I spent the next week getting absolutely horrible sleep. I'm a total champ at sleeping so this was weird for me. I moved the clock across the room and instantly, my sleep was all better, totally normal. The clock was the only thing that changed in my sleep getting worse and then better.
So, I'd say if you are having trouble sleeping, it's worth moving any electronics that are near your head and seeing if that helps out at all. In addition to the long checklist of other factors you should be looking at, naturally.