I would try to smoke a few bowls of english blends and see if you can detect much ghost. Sometimes you can, sometimes you can't. If it's not too strong, it will smoke out pretty quickly. You can ream it (or have it reamed), but it may not be necessary unless the ghost is very persistent.
If there's a strong and stubborn ghost in there, you'll likely need to perform the salt and alcohol treatment (I use cotton balls instead of salt, but it doesn't seem to concern most folks). If you do a google search on that you should get lots of hits. It basically involves filling the bowl and shank area with cotton and soaking the cotton with whatever alcohol you use to clean your pipes. Let it sit for a day or so and pull out the cotton and the ghost usually comes with it. If not, you can try again or you can try with vinegar instead of alcohol. It sounds awful, but many people more experienced than I have been successful with that.
There's also the pipe cleaning retort, but your on your own there. I don't like mixing alcohol and flames in the house.
The salt/cotton and alcohol treatment and retort are really to be saved as a last resort type thing. They won't damage your pipe if done correctly, but often times they are unnecessary.
Good luck!
