Non-Intrusive Load Monitoring (NILM) is a promising technique for disaggregating per-appliance energy consumption in buildings from aggregate voltage/current measurements. One major limitation of the approach is that it typically requires a training phase during which users must manually label device transitions. However, inexpensive contactless electromagnetic field (EMF) event-detector can detect appliance state changes within close proximity based on magnetic and electric field fluctuations. Each detector wirelessly transmits state changes to a circuit-panel energy meter, which can then be used to label and disambiguate appliance transitions detected from the aggregate signals as well as to track the associated energy consumption. We want to experimentally evaluate the EMF sensor in terms of power consumption, accuracy and detection range on a variety of appliances to demonstrate its effectiveness towards augmenting NILM systems.