In the epilogue of "The Wrath of the First Lantern" story arc in Green Lantern #20 Larfleeze (the only Orange Lantern) revealed his oath and his ring charged to 100% and it is as follows:
"What's mine is mine
and mine and mine,
And mine, and mine, and mine!
—Larfleeze, Green Lantern (vol. 5) #20 (May 2013)
The only thing I could find that resembled the oath you have written is from a CBR Forum from 2008 where the participants were making their own Lantern Oaths. What you have found was considered to be one of the most popular ones. Here is the text:
Default Make Your Own Lantern Oath!
Well folks, with the Rage of the Red Lanterns up and running, we've got upwards of three, count 'em, THREE different Corps out there, each with their own rhyming oath. But we still have FOUR other Corps out there each one probably with their own oath. There's Blue (Hope), Orange (Avarice), Indigo (Compassion) and Violet (Love).
So I put it to you, "CREATE THE NEXT LANTERN OATH." Just choose a color that hasn't had their oath written yet and let your inner poet free.
I'll get started, with the Orange Lantern oath of avarice.
This power is mine, this is my light.
Be it in bright of day, or black of night.
I lay claim to all that falls within my sight,
To take what I want, THAT IS MY RIGHT!