Oil in Number One Cylinder

My 2000 Prizm was starting to run a little rough, and it was about that time, so I changed the spark plugs yesterday. I got a nasty surprise when I pulled out the plug for the number one cylinder (the furthest left one) and it was dripping in oil. I'm guessing the seals/gaskets have deteriorated, and too much oil got into the cylinder, fouling the plug and then accumulated as it did?

My father-in-law suggested replacing the plug anyway, drive it for a couple hours and see if the oil burns off. Sounds logical, but I'm wondering whether the plug will even fire if there's that much oil in there. Moreover, it could be the ignition coil is bad (I might run to AutoZone today to borrow one of their testers).

Any thoughts, suggestions, similar experiences, and/or warnings?

Thanks!

John

Compression Test. The Readinds Should Be Similar On All Cylenders

John-

I replaced the plug and checked it three days later--it burned off all the oil and looked clean. Should I do the compression test anyhow just for the heck of it?

If so, two stupid questions: can a novice like me do it at home (with, say, a rental tool from AutoZone), and what exactly does a compression test measure?

Thanks!