Strange sound showing up in my recording

Hi friends,

I recently moved o a new office and I noticed that my recordings all have a strange "radio frequency sound"? Im not even sure if that is what it would be called. I have tried different things like a ground loop thingy, and different outlet for my recording device. No go. Any help would be wonderful

Good morning Paul. This problem happens more then most people realize.

Does your office have florescent lights?