What is causing spark plugs to fail?

I have had to replace the spark plug on cylinder 2 twice in
the past 6 months. Is there any obvious things which could
be causing that spark plug to fail? After replacing the
sparkplug the first time the issue was fixed for a couple of
months. Recently I needed to replace it again. I've noticed
that occasionally at low rpms/ idling the service engine
light will start to blink like it did when the cylinder was
misfiring  before I replaced the plugs. Could there be
something causing the plug in cylinder 2 to fail?