Just remembered this one.

When I was relatively little, around 6-8 years old, I had this dream where I was walking through the grass and I fell into a wide hole. Some of my family members were calling out to me, and the hole was too deep to climb out of. Suddenly I could hear a disembodied British female voice speaking to me in sentences that didn't make much sense. I gathered from what she was telling me was that I should go a certain direction, and so I walked into the side of the hole, phased through, and blacked out.

I woke up in what looked like my parents' bedroom at my childhood home, but it was underwater and all the things were made of coral and anemones and stuff. I think the White Rabbit from Alice in Wonderland was there, and he showed me the way out. I ended up back in the hole, and tried the other direction. This time, I was teleported out of the hole, and was reunited with my family.