(This limited form of Craft Wondrous Item was going to be one of the powers of the Mystic Wanderer prestige class in Magic of Faerun, but it was decided that it wasn't as noteworthy as Gem Magic. If you want to play the Mystic Wanderer (the 2E mystic class) in its traditional sense, here's the info on Candle Magic. Note this has nothing to do with the Candle Caster prestige class from Tome & Blood.)
The woman was barefoot and wore a form-fitting dress of gray and green,
her sleeves ragged, her ears pierced a dozen times with ivory talons. Despite
her bare feet and worn clothing, she was beautiful, and bore an aura of confidence
and power, and danger as well. By contrast, the young nobleman was dressed
finely, every hair oiled into place and his jewelry polished, and in her
presence he was as deferential as a cowed servant.
"So can you help me, servant of the Plague Mother, against Sevastrian, my rival?"
"Yes," purred the woman, her dark eyes flashing. She pulled a small black candle from a leather pouch at her side. "Get him to burn this, under any circumstances, and he will soon be ignored by your lady love, and most others."
"And what is the price of this item?"
"I want your signet ring. And a service to be named later. I will find you."
The man shuddered, despite his attraction to her. He nodded, gave her his ring, then took the black curse candle, and departed.
Candle magic is a specialized sort of item creation practiced primarily by mystic wanderers (see the Mystic Wanderer prestige class in Magic of Faerun). It allows the user to craft magical candles that activate when burned (requiring a standard action to light and one full round for the magic to activate). The candles are otherwise normal use-activated single-use wondrous items. Any character with the Craft Wondrous Item feat can create magical candles, but the majority of them are made by mystic wanderers.
The most famous types of candles made by mystics are the red love candle (which functions like a potion of love), blue protection candle (which functions as a magic circle against chaos, evil, good, or law, as set by the creator), purple truth candle (which functions as a zone of truth), gold healing candle (which functions as a circle of healing), yellow telepathy candle (functioning as speechlink), green fortune candle (functions as prayer), white purification candle (break enchantment or dispel chaos, evil, good, or law, as set by the creator), silver empowerment candle (works as incense of meditation), or the dreaded black curse candle (which places up to six bestow curse spells upon a target).
(If you wanted to treat this as a feat, I'd consider giving either a slight discount on the cost to reflect the one-round activation time, or reduce the required caster level to take the feat by 1 level.)