Santa needs help finding a chapter book with purple covers

Hello! First time poster in need of some help, please. Santa is desperately searching for the name of a chapter book. The grade school reader doesn’t remember the title after seeing it in a store.

The cover is purplish with a house or mansion and has two kids going up to it to open the door. Any help would be much appreciated. Thank you!

Update with some more detail from the reader: The book is apparently about two siblings who go to their grandfather’s house in the woods for a summer trip, only they find that the grandfather isn’t there, and he’s missing. They spend the summer trying to find him. It might be they start to suspect he’s magic, and that the mansion is magic.

Thank you!!

Is this a book currently in book stores now?

Not an exact match, but maybe Finch House?

>2 ImShaunie: it is! Thank you for replying!

>3 rarm: thank you for replying! I don’t think so.

Sorry I can't be of more help, but has Santa tried going to the store and looking around/chatting with a shopkeeper? My local bookstores often display books which come from local authors, and if the book Santa is searching for is one of these, I'm afraid the internet will not be able to find it in time.