User blog comment:Kaido King of the Beasts/Future Devil Fruits/@comment-72.171.192.122-20151017063608/@comment-67.204.208.3-20151018052515

Enel could not control radio waves or microwaves; he could only manipulate lightning. No part of the spectrum of electromagnetic frequencies has anything to do with Enel's powers.

But even if this fruit couldn't control electricity, controlling electromagnetic waves could still be a very versatile power. Depending on how vague the power is, the entire wave spectrum could expand to visible light, meaning the user could turn themselves, or others, invisible. Or using microwaves, they could blast enemies with heat. X-rays might let them see through walls, and manipulating sound waves could allow them to mimic someone's voice, or paralyze enemies with a scream.

For a creative user, the possibilities are basically endless, but I feel like that might make it a bit OP.