Stop worrying about turning your bathroom exhaust fan on and off. Instead, install a humidity sensor that automatically controls the fan switch.
Installing a humidity sensor in your bathroom is a project most DIYers can handle on their own, and one that could save your walls from mildew problems later. Having a modicum of electrical experience is helpful but not necessary, as long as you follow some basic safety standards.
Bathroom exhaust fans are vital to controlling air moisture levels while taking a bath or shower. This is important to prevent mildew and mold from taking hold on your walls or ceilings. Most people turn off the fan as soon as they're out of the shower, but that's a mistake. The fan should be left on for a few minutes after your shower to get the air back down to an acceptable moisture level.
The tough part is remembering to go back later and turn the fan off. This is an especially hard concept for kids to understand, as they are always off to the next thing. If left on, the running fan wastes electricity and shortens the lifespan of your fan. So, install a humidity sensor that's connected to your fan, and automatically shuts it off when appropriate.
In the video above, an electrician demonstrates how to install a humidity sensor as well as adjust it to meet your humidity control needs. The Leviton sensor shown also has a manual on/off control and requires a switch box with a neutral wire to install.