DC output of phone charger
Some regulated supplies (cheap switchers) allow their outputs to drift high  when completely unloaded. With a typical load they will work correctly.
What's happening is short duration switching spikes containing very little energy are rectified and gradually charge up the smoothing capacitor. Because they have very little energy this only affects the output voltage when the supply is unloaded. 

Re-measure with a minimal load (maybe 10ma, or a 500 ohm resistor) and the voltage may be much closer to nominal. If it's still over 7V you have an unregulated supply.

The designers assume that because no load is connected, this deviation from the specification doesn't matter. And for the original application, they are correct; however if you are using the supply for another purpose, beware ... or take appropriate precautions - like wasting 10ma in a resistor!