Is there an outlet around your home that wont hold a plug whatever you do?
Well, it may have gone loose because of using it too much over time.
kick off the outlet and check whats wrong inside.

Image credit: Everyday Home Repairs via YouTube
Remember that the gold screws are on the hot side and the silver ones are neutral.
First, hook the ground wire around the ground screw using pliers, then close it securely and tightly.
Push the outlet to the wall, then tighten the screw to secure it in place.

What To Do When A Plug Wont Stay In The Outlet
