How do I get a broken piece of a plug out of an electrical outlet without calling an electrician?

So this morning i was in my room with my heater, it started to get a little hot in the room so i turned the heater off and unpluged it. When i noticed that the piece of the plug was stuck on the wall, i dont want to touch it because i dont want to get electrocuted,what do i do to get it out of the wall?