To get chocolate off the wall, allow the chocolate to harden if it already hasn't.
Then scrape off any excess hardened chocolate from the wall.
After you scrape off any dried or hardened excess chocolate from the wall, you can blot the area with a clean cloth that is dampened with some warm water.
You can also use a solution of warm water and mild detergent or soap to help clean the chocolate off the wall.
If the chocolate on the wall is still not coming off easily, you can use a cleaning eraser or all purpose cleanser.
If the stain from the chocolate is still visible you can also paint over the chocolate stain so that it's no longer visible.
Dried and hardened chocolate on the wall is easier to remove than melted chocolate as melted chocolate can smear around the wall when you try to clean it off.
When the chocolate dries it can be easily scraped off in most cases.
Mild dish soap and water is a good way of getting chocolate off of walls even when melted or dried.
Oxidizing stain removal powder or some dry cleaning solvent and a rag or sponge can also help remove chocolate from the wall.
You can also use a teaspoon of clear ammonia with a cup of warm water and use it to clean the chocolate off the wall and the chocolate stains.