what causes oil to leak on spark plugs and how do i fix it? on 1996 Oldsmobile Aurora

i had my spark plugs changed and found out my plugs were getting oil on them

Asked by for the 1996 Oldsmobile Aurora
It's not head gaskets. Replace the valve cover gaskets.
2 more answers
All you need is a valve cover gasket set . This set should cost around 80-120$ dependig on what engine you have in your car. Labor not too much eather.
Most probable cause is the head gasket has worn out allowing oil to seep through to the plugs. If you don't want to replace it go to a parts store and get a good gasket sealer additive for the oil and hope for the best after about 200-500 miles. Otherwise the likely solution is to replace the head gasket.