Here's a photo of an online seller's offering of an insulator mold to make your own Italian porcelain insulators, I believe the 2UM style. Beware of any wild colors or glazes found in this or similar styles. Authentic ancient factory examples are known to exist (some with beautiful red or blue or green stripes) so its important to educate yourselves. This particular orange glaze is not a true historical color.

The seller notified me the mold is designed to make candles (presumably with wax).