PC switching on/off mystery [solved]

Funny story really.

Last night I was trying to explain to my 10yr old daughter how a transistor worked (I think I failed) so ok I got to the breadboard disconnected my power button to my desktop, ran 2 long wires to the power jumper pins to my breadboard.

Connected up an NPN transistor, 5v on the Collector, 0v on the emitter then i ran 2 free wires, 1 to the + side, and then a free jumper wire into the air.

So, then, Dayna, watch this, you grab this wire (Base) I grab the 5v cable (5v rail) and then i got her to touch my hand with her finger and sure enough the computer sprang to life (no current limiting resistors, the current was barely detectable had to squeeze hard on the pin to get it to detect) .... so anyway come this morning, the computer was on, went for a drink came back it was off!

never thought much of it until it shutdown again!

LOL, I forgot I left it all connected on the breadboard, everytime someone switching on a light or turned on something generating a bit of EMF, my PC turned off!