Can't search for "vampire" on the Exchange

Sorry that I hadn't gotten back to you with this.

I just did a look and found this house built by Hidehi. The house was built on a 28x22 with 3 bedroom - one with a crib and one with a vamp in mind.
https://www.thesims3.com/assetDetail.html?assetId=9228618

Here is one on a 20x30 called "Axom's Lair".
https://www.thesims3.com/assetDetail.html?assetId=9168682


I know you don't you don't have 60x60 or 64x64 lots listed as what you want but I will list them anyhow just in case the creators might havr other lots built for vampires in mind... :)

Here is another by Hidehi. But it's on a 60x40.
https://www.thesims3.com/assetDetail.html?assetId=9199777

Hidehi created these houses as well as some community lots for RFlong7's Supernatural world.

Here is one called "Vampire Mansion" created by ktward08 but it's on a 64x64 lot.
https://www.thesims3.com/assetDetail.html?assetId=9228751

Here is one that is a castle but that too is on a 60x60 lot.
https://www.thesims3.com/assetDetail.html?assetId=9207116

Here is a 10x10. And yes, I know you didn't request this size as well but again, I'm posting the link just in case the creator has other builds for vampires... :)
https://www.thesims3.com/assetDetail.html?assetId=9160174

Here is one that is a 30x30 lot.
https://www.thesims3.com/assetDetail.html?assetId=9149642

Hope you find what you're looking for to place in your game... :)