I'm trying to find a poem about a visitor who enters this household and becomes a very bad influence on the family. The father never asked the visitor to leave and remains to negatively impact the child. In the end, we find that the influence is a television. Can someone help me?

I found this by Roald Dahl --

Television

The most important thing we've learned,
So far as children are concerned,
Is never, NEVER, NEVER let
Them near your television set --
Or better still, just don't install
The idiotic thing at all.
In almost every house we've been,
We've watched them gaping at the screen.
They loll and slop and lounge about,
And stare until their eyes pop out.
(Last week in someone's place we saw
A dozen eyeballs on the floor.)
They sit and stare and stare and sit
Until they're hypnotised by it,
Until they're absolutely drunk
With all that shocking ghastly junk.
Oh yes, we know it keeps them still,
They don't climb out the window sill,
They never fight or kick or punch,
They leave you free to cook the lunch
And wash the dishes in the sink --
But did you ever stop to think,
To wonder just exactly what
This does to your beloved tot?
IT ROTS THE SENSE IN THE HEAD!
IT KILLS IMAGINATION DEAD!
IT CLOGS AND CLUTTERS UP THE MIND!
IT MAKES A CHILD SO DULL AND BLIND
HE CAN NO LONGER UNDERSTAND
A FANTASY, A FAIRYLAND!
HIS BRAIN BECOMES AS SOFT AS CHEESE!
HIS POWERS OF THINKING RUST AND FREEZE!
HE CANNOT THINK -- HE ONLY SEES!
'All right!' you'll cry. 'All right!' you'll say,
'But if we take the set away,
What shall we do to entertain
Our darling children? Please explain!'
We'll answer this by asking you,
'What used the darling ones to do?
'How used they keep themselves contented
Before this monster was invented?'
Have you forgotten? Don't you know?
We'll say it very loud and slow:
THEY... USED... TO... READ! They'd READ and READ,
AND READ and READ, and then proceed
To READ some more. Great Scott! Gadzooks!
One half their lives was reading books!
The nursery shelves held books galore!
Books cluttered up the nursery floor!
And in the bedroom, by the bed,
More books were waiting to be read!
Such wondrous, fine, fantastic tales
Of dragons, gypsies, queens, and whales
And treasure isles, and distant shores
Where smugglers rowed with muffled oars,
And pirates wearing purple pants,
And sailing ships and elephants,
And cannibals crouching 'round the pot,
Stirring away at something hot.
(It smells so good, what can it be?
Good gracious, it's Penelope.)
The younger ones had Beatrix Potter
With Mr. Tod, the dirty rotter,
And Squirrel Nutkin, Pigling Bland,
And Mrs. Tiggy-Winkle and-
Just How The Camel Got His Hump,
And How the Monkey Lost His Rump,
And Mr. Toad, and bless my soul,
There's Mr. Rate and Mr. Mole-
Oh, books, what books they used to know,
Those children living long ago!
So please, oh please, we beg, we pray,
Go throw your TV set away,
And in its place you can install
A lovely bookshelf on the wall.
Then fill the shelves with lots of books,
Ignoring all the dirty looks,
The screams and yells, the bites and kicks,
And children hitting you with sticks-
Fear not, because we promise you
That, in about a week or two
Of having nothing else to do,
They'll now begin to feel the need
Of having something to read.
And once they start -- oh boy, oh boy!
You watch the slowly growing joy
That fills their hearts. They'll grow so keen
They'll wonder what they'd ever seen
In that ridiculous machine,
That nauseating, foul, unclean,
Repulsive television screen!
And later, every kid
Will love you more for what you did.

That's not the one. The one I'm thinking of depicts the TV set as a person in the beginning. We later find that the guest or visitor is a television set. Thanks for responding though!