A man watching telly receives a package and it's a teddy bear. Doesn't think anything of it but then opens the stuffing out of the bear to find a VCR cassette tape. He plays it and there's some spooky horror. Then as he's finished watching it he goes to another room and en route a monster pulls him through the wall. It ends there. I'm sure this was a British short film.
According to Cambridge Cinema Short it's about:
A lonely man with a dark past and the horror beneath his feet.
One reviewer noted that:
Insides by Dan Gitsham introduced a completely contrasting genre. Incredibly atmospheric, I was unsure of what to expect as the lone man wandered around his empty, cluttered house.
At the discovery of an oddly placed video cassette inside a stuffed toy under a floor-board – having been a reluctant viewer of ‘The Ring’ – I knew it was time to hide.
I know you've searched long and hard for this one. Enjoy the show!
~ Screenshots taken directly from the video