Now it depends just what the 'electricians screwdriver' is.If your referring to one of those little screwdrivers with a neon lamp in it then NO you have not got an electricians screwdriver as they will not use them, remove the neon, don't ever use it to see if there is any voltage. search and you will find out why.
I agree the neon type are not much use, however the LED type with a couple of button cells are brilliant and I have a few of them.
Yes they can give unexpected signals but like any other tool or piece of test kit one has to learn how to use them. For fault finding and circuit tracing in control panels they tend to be my first port of call as I usually have one in my pocket.