If i leave my laptop AC adapter plugged into the wall, but not into the laptop, is there any danger that someone or something could get shocked or electrocuted by touching the end of the adapter that goes into the laptop?
I've also heard that leaving the adapter plugged in, even if not in use, still uses electricity, thus costing me money. Is that true?
As far as the electrocution part is taken into account.... YES.... that is very much possible if there are other problems with the Wall outlet like earthing problems or a short etc. It is advisable to leave the switch off if you wouldn't want to remove the adapter and plug it in every time. Just hit the switch....
As far a consuming electricity is concerned.... as long as the circuit is not complete.... meaning the laptop is not connected you will not see the consumption go up.... unless again there is a leak in the circuit.