Hi,Welcome to Just Answer, My name isXXXXX will be helping you with your appliance issue today.
its your Thermal fuse. If the dryer overheats, this device stops the flow of electricity to the heat source and/or the entire dryer. It is located on the blower housing and cannot be reset. The most common cause for overheating is a vent tube clogged with lint, a birds nest or other debris. It doesn't necessarily have to be caused by a vent clogged but that's the most common reason, it may have just blown on its own, this happens quite frequently, this is what the thermal fuse looks like, you can order one of these at the following link, there is also a video there to show you how to test it with a voltmeter if you have one, http://www.repairclinic.com/PartDetail/Thermal-Fuse/2986 it's part number 7 on this diagram, to get to it you will need to remove the back panel on the dryer, just pull a dryer away from the wall carefully shut the gas off, and remove the back panel make sure the dryer is unplugged also, when you get the panel off you will see this on the blower assembly in the bottom left side when looking from the back of the dryer, this will take care of your issue, thanks and well wishes, Bryan