Actress Hailee Steinfeld pairs a navy-and-white dress with white strapped sandals at an event in Los Angeles in 2013.
If the oil is on the inside parts of the spark plug like the bottom insulator, that's a bigger issue, you have either leaking valve seals or very leaky piston rings. If your car blows a puff of blue smoke on startup, you probably ave leaky valve seals. If it blows blue smoke all the time, leaky piston rings.
Moisture condenses on the inside of all oil tanks and settles to the bottom to form an acidic sludge. Over time, this sludge build-up attacks the metal and can cause the tank to leak from internal corrosion. Internal corrosion typically causes pin hole leaks that drip slowly under the tank.