At my parents house, they have a single pole light switch and a duplex outlet in a double gang box. It quit working last week so the landlord came and rewired it. My mom has the microwave plugged into the outlet and the switch turns on the ceiling fan. After their landlord rewired it, when my mom turns on the microwave, it starts up and then everything just browns out on the microwave and it turns on the fan until you push stop on the microwave. It only does it with heavier appliances such as vacuum. The fan works fine without anything plugged in. My mom moved the microwave to a different plug and she doesn't use the fan. Can't get ahold of landlord and he doesn't want us doing anything to the house. I'm just curious of why this would be. Any info would be appreciated.