Sue has a strange problem that her TV screen image flips every time she uses the microwave. Leo says that microwaves are usually shielded, so there's nothing to really worry about. But the cord may not be shielded. So the interference from the power is messing with the HDMI cable. It could also cause the computer to act funny if they're on the same circuit. She can get something called a CHOKE, it's a big bump on a power cable. She'll see them on laptop cables. They're magnetic cores that snap onto a cable that blocks RF signals from coming out of the power cable. And they're cheap at about $5 a piece on Amazon.
But if she's concerned about her microwave leaking, it's possible. Return it and get a new one. Doctor Mom says to put a piece of mylar on the door and see if it stops. If it does, her microwave is leaking and needs to be replaced.