olyteddy meter and the Fluke 117 meter has a LoZ function that you can use to see if that voltage you are reading can do actual work by putting a load on the circuit.Very good feature in a meter.
More here. LoZ stands for Low Imped- ance (Z). This feature presents a low impedance input to
the circuit under test. This reduces the possibility of
false readings due to ghost voltages and improves accuracy when testing to determine absence or presence of voltage.