Yes, sticking a fork (or any metal object) into a toaster is extremely dangerous and should never be attempted. Toasters work by passing an electric current through the heating elements to generate heat, which toasts the bread. When a metal object, such as a fork, is inserted into the toaster, it can create a direct electrical connection between the live electric components and the grounded metal of the toaster.
This can lead to a serious electric shock or electrocution hazard. Electric shocks can cause burns, injury, or even be fatal in severe cases. Moreover, inserting a metal object can also damage the toaster or cause a short circuit, leading to a potential fire hazard.
If something gets stuck in a toaster or if you need to retrieve something, always make sure to unplug the toaster first before attempting to remove the object. Alternatively, you can turn off the toaster and wait for it to cool down before attempting to remove the item with non-metallic objects like wooden or plastic tongs.
Always prioritize safety when dealing with electrical appliances and never insert metal objects into a toaster or any other electrical device while it is plugged in or powered on.