Electricity that comes to your home is generated by massive electric generators and those electric generators are running and producing electricity constantly and whether or not you use that electricity it's still be generated and just wasted if you're not using it.
So actually by not using electricity while it's being generated you're actually wasting the energy that is being used to generate that electricity for you to use.
So you're not actually saving the planet by shutting the light bulb or anything else that uses electricity off.
So no it's not actually possible to waste electricity and really the only harm you'll do when wasting electricity is just spending more money by raising your electricity bill.