LEDs do not make radio
interference it is the power supply that makes the interference. Switch-mode power supplies must be designed initially with EMI minimisation in mind from the beginning. Those running light manufactures who do utilize the RAdio
Shack method of design are not power supply designers. There are switch-mode supplies that are designed to drive LEDs without generating interferencs. Problem is that we buyers do not know which products are designed with minimum EMI in mind.
LED assemblies made without switch-mode supplies merely burn up excess power as heat and, therefore, are way less efficient than those designed with switc-mode supplies.
We must look for LED assemblies that have good swich-mode supplies and good optics and good LED quality. Not cheap