wax, candle, waxy, glazed, maggot
蜡 centers on waxy substances and their uses, such as candles and glazes, but also extends to the unrelated meaning of maggot, likely due to the insect radical.
蜡 combines 虫 (insect) with 昔, which likely contributes the sound. The connection to wax may come from insect-derived waxes, while the maggot meaning directly relates to the insect radical.
An insect (虫) from the past (昔) leaves behind a waxy substance, like beeswax, or appears as a maggot.
For ショ, imagine a show where a candle made of insect wax is the main attraction: show -> ショ, and the candle's wax comes from the insect.