Electronics stores carry it as well although a bit more pricey than say NAPA.
And just a bit of an FYI, that same stuff has been some of the best gasket sealer available. Put some between your thumb and forefinger and rub it into the gasket before assembly. Seals very well, renders the gasket removable with no scraping, and many permits reuse when in a pinch. Been doing it on my 2 strokes for over 40 years and works great.