We're very fond of the tarts that pop out of toasters. I like the blue berry ones the most.
Can you give me the location of the portal, and that way I can see if there's any residue left behind, to find a point of origin?
Truly. If it's a demonic presence, or even a lesser imp, you'll need trick it to be rid of it. Otherwise, it will become defensive and very stubbornly refuse to leave. And no one likes the effects of a demon overstaying its welcome.