It is on the third story of the Haunted House, in the fireplace. (You need to align the clocks on top of the fireplace so they will meet at midnight.)
You will get it from the fire then go to the kerosene and fill the lantern up.
You get the lantern and light it with the kerosene.
The jack'o'lantern is a costume, previously available in the Poptropica Store.
When you get the lantern go down stairs and find a barrel and click it. Then the lantern will light up.
To light the lantern in the haunted house you have to go to the floor you came in on and click on the kerosene barrel.
You go to the ghost cat and click on him.
matches loch ness lantern himilaya
You find the Karosine by the stairs in the cellar.
There is a barrel of kerosene under the stairs in the basement (where you entered). Click on it to fill the lantern.
The monk from the Himalayan temple gives it to you.
It is red... like your average lantern.... you have to play with the clocks to get it though... look up "Haunted House Poptropica Walk-through if you want to know how to beat the clocks.
go to the place with the boiler. by the stairs there will be a barrel that says kerosene. click on it and your lantern has fuel.