Its hard to make out the unit, but the first picture looks dangerous or done quick, so no plants or watering there.
Is the first picture an element circuit of some kind, i can make out a bi metallic switch contacts, and what looks like a neutral wire connected to a ground wire, looks like the blue neutral did not reach its termination, or something like that.
Ive got to be honest the wiring in the first picture looks like a death trap, not something i would be happy with.
The unit you describe for wax melting, i know what they are, but what that is looks dodgy, go buy a new unit, or build a new one using low voltage and maybe nicrhome wire, but a hefty psu will be needed, or build a mains unit thermally controlled for optimum wax melting.
The later needs experience and a complete understanding of mains working and safety.
Dave.