The Wikipedia article for Maha Shivaratri narrates a story of how a hunter accidentally performs abhiseka of a Shiva linga using Bael leaves on the night of Shivaratri and goes to Sivaloka (Kailasa) upon his death:
Once upon a time, King Chitrabhanu of the Ikshvaku dynasty, who ruled over the whole of Jambudvipa (India), was observing a fast with his wife, it being the day of Maha Shivaratri. The sage Ashtavakra came on a visit to the court of the king.
The sage asked the king the purpose of his observing the fast. King Chitrabhanu explained that he had a gift of remembering the incidents of his past birth, and in his previous life he had been a hunter on Varanasi and his name was Suswara. His only livelihood was to kill and sell birds and animals. The day before the new moon, while roaming through forests in search of animals, he saw a deer, but before his arrow flew he noticed the deer's family and their sadness at its impending death. So he let it live. He had still not caught anything when night fell, so he climbed a tree for shelter. It happened to be a Bael tree. His canteen leaked water, so he was both hungry and thirsty. These two torments kept him awake throughout the night, thinking of his poor wife and children who were starving and anxiously awaiting his return. To pass the time, he engaged himself in plucking the Bael leaves and dropping them down onto the ground.
The next day he returned home and bought some food for himself and his family. The moment he was about to break his fast a stranger came to him, begging for food. He served the food first to stranger and only ate afterward.
At the time of his death, he saw two messengers of Lord Shiva, sent to conduct his soul to the abode of Shiva. He learnt then for the first time of the great merit he had earned by unconscious worship of Shiva during the night of Maha Shivaratri. The messengers told him that there had been a Lingam (a symbol for the worship of Shiva) at the bottom of the tree. The leaves he dropped from the Bael tree had fallen into the shape of a Lingam, in imitation of Shiva's ritual worship. The water from his leaky canteen had washed the Lingam (also a ritual action), and he had fasted all day and all night. Thus, he unconsciously had worshiped Lord Shiva. At the conclusion of the tale the King said that he had lived in the abode of the Shiva and enjoyed divine bliss for a long time before being reborn as Chitrabhanu. This story is narrated in the Garuda Purana. 
 Garuḍa Purāṇa 1.124
Now Garuda Purana (Chapter 124) has a slightly different story, in that, the hunter's name is Sundara Sena and not Suswara. And it doesn't mention anything about him reincarnating as Chitrabhanu of the Ikshvaku race:
Once upon a time, the vicious Sundara Sena, the king of the country of Arvuda, went out, with his dogs, on a hunting excursion in the forest. But the day wore on and night came without any game even being sighted. The hunter, hungry and jaded with the day's trouble, sat down weary and watchful in a bower on the bank of a pool on the hillbrow. But lo, there happened to be a phallic emblem in that bower, and the leaves of the Vilva tree, which was shaken by the impact of the hunter's body as he strove to lie down on the ground, rustled and fell in heaps over the emblem, without his knowledge. The fowler fetched water from the pool and sprinkled it over the floor of the bower to lay down the dust ; and drops of water thus dribbled down over the head of the emblem from the tips of his fingers. Suddenly there fell down a shaft from his quiver on the ground, and the fowler crawled on his all fours to lift it up, when unknowingly he touched the emblem with his chest. Thus he touched and bathed and worshipped a phallic emblem on the night of the Vratam, which he passed in a vigil, though for quite a different purpose.
The fowler returned home on the following morning and took his meal with his wife and children. So years came and years went away, and the fowler died a natural death at the end of his appointed days, when the emissaries of Death came to take his unclean spirit in fetters to the mansion of their lord. But lo, my own warders sprang upon them, and overpowered them in the scuffle that ensued, and finally brought him, a free and unfettered spirit, to my own special region of bliss (Siva-loka) in the company of that faithful dog which watched by him on the night of the chase in the bower.
This blog post claims that Bhishma also narrates the story to Yudhishtira while lying on the bed of arrows:
Different Version of the Legend (Story of King Chitrabhanu):
Shanti Parva of the Mahabharata, talks about the legend of King Chitrabhanu observing the festival. The story, as told by Bhishma while resting on the bed of arrows and discoursing on Dharma...
How to reconcile these different accounts of the same story?