why is oil around my spark plugs on 1999 Lexus GS300

I pulled out my spark plugs an oil was on the end of them

Asked by for the 1999 Lexus GS300
oil on the electrode??bad motor sorry dude
so do u think a rebuild kit will be the best answer or buy a new motor I also had someone tell me it could be the valve covers
where is the oil exactly,,the part in the motor or outside the block
inside around the spark plug 1mechanic says theres nothing wrong with the motor but there are worn parts in it so he would jus get a rebuild kit another told me that there is a seal somewhere around the valve covers that might be letting oil get on my spark plugs p.s my car dors have 295,000 miles
Valve cover gasket set will fix the problem. You had oil on top of spark plug but aftr you pulled out the oil drain down to the tip.