Fluorescent lights can interfere with an FM radio by emitting electromagnetic radiation commonly known as radio frequency interference or RFI. Most modern fluorescent lights of good quality will not interfere with an FM radio. However, not all lights and their fixtures are made to the same standards. Checking to make sure your radio is working efficiently is a simple way to keep RFI from affecting performance. If all else fails there are inexpensive products on the market to eliminate radio interference.
Examine your radio. If it has a boom box style telescoping antenna it may have become loose from being moved around. Try tightening it with your fingertips to eliminate the RFI. If your antenna is the lamp cord style, make sure it is secured tightly to the back of the radio. Move the antenna cord around and see if the interference stops. Try shortening the length of wire between your radio and speakers. Long speaker wire can pick up RFI and make it louder. Consider moving your radio to a different location. Moving your antenna to a new area may improve your reception enough to overcome the interference from fluorescent lights. You may also find that plugging it into a different wall outlet eliminates RFI.
Check the fluorescent lights. Lights that are not working efficiently tend to emit increased RFI. Fluorescent lights naturally make some low buzzing or humming sounds. Pay attention to whether the sound is more noticeable than it used to be. An increase in the sound can be an indicator of a light or fixture that needs to be replaced.
Consider installing a radio frequency interference filter. These inexpensive filters can be as cheap as a few dollars. Simply snap it on the power cord at the back of the radio to eliminate any RFI being emitted from your fluorescent lights.
Fluorescent lights that flicker after being on for a while may have become defective and need to be replaced. Never coil excess speaker wire. It can act as an antenna and pick up sources of interference.
Always make sure the power is turned off before examining any radio or light fixture.