A quick and simple toroid current sensor to determine if an AC appliance is drawing power and roughly how much.
This was made as a simple proof of concept for an idea found on FirstBuild about monitoring when a washer/dryer finishes and alerting the user through a text message, email etc.
FirstBuild Project: https://firstbuild.com/eric.tauzer/cycles-done-add-on/
You might have to rectify and amplify the signal but you can then feed it into an Arduino as an analog input. I would recommend more turns of wire on the toroid.
The toroid was removed from a broken CFL bulb.