Regardless of wiring you are going to be safe. What @Sharptooth said about him getting a shock is because he was messing with bare wires and being unsafe. It happens to the best electrician..
In certain extreme cases touching earth can give you a shock but that is very rare situations.
Remember that an entire appliance is earthed, so if you hold a metal light that has earth on it, it the same as holding the earth pin on the plug while plugging it in. Allot of new electricity regulations require homes to be fitted with sensitive earth leakage detectors. So before a lethal welding iron type shock can be inflicted.. the electricity will trip within hundreds of a second, saving your finger or life..
But in terms of home use, well look at this 3 prong plug

Its a UK version, but in africa thay are round with the same distances. Now notice the longer one. the one you mention to navigate with your finger. It is completely exposed and longer than the others. Its functions are as follows:
- Extra distance ensures the device is grounded before any current is applied to it
- enables plugs with safety pins to disengade and allow the plug to enter
If.. you wiring is faulty any device plugged in will cause the breakers to trip before it has a chance to shock you!
The two shorter pins and its construction functions as follows:
- Only the tips are exposed to ensure that contact is ONLY made once the plug is within the wall socket to prevent shock in case you have your fingers there.
Right, so you dont have to worry about your wiring but what is important the plug you are using. You want to guide it with your finger then get a plug that looks like that.
Because I tell you what.. if you decide to do the same with these Eastern European Plug

You will fry your finger.. But inspecting this plug you will notice that it actually may seem easier to plug it with out feeling with your finger if its aligned because it has guides to help you align before plugin in.
Here are some plugs that will cause you harm if you keep your finger near the pins while pluggin in...

It is important to realise that poking your fingers around electricity is never a good idea any way.