dimming led lights - Flickering & EMF

OK, there may be some very small field, and the wife of one friend actually owns an EMF detector device, for which she paid a whole lot of money that she could not afford to spend. And it has a very impressive multi-line LCD display and a very impressive probe that looks "really sensitive." Unfortunately I do not recall the units of it's measurement, except that they were metric. (of course) I am guessing that it also detects electrostatic fields as well. It does have several impressive knobs and selector switches.
And it seems that I need to correct my claim, to the extent that there are no significant electromagnetic fields, except inside those MRI machines.