What made Mrs. Hall think that there were spirits in the room? What did she guess about the stranger?

When Mrs. Hall pops her head round Griffin's door, she gets the fright of her life. In the strange guest's room there are blankets, pillows, and items of furniture frantically swirling around in the air; it's as if the place is haunted. Indeed, Mrs. Hall thinks it is. She's already clocked her new guest as more than a bit weird; he always keeps himself to himself, never talks to anyone, never goes to church, which in this neck of the woods is tantamount to Satanism. But now she's convinced herself that this funny man's actually been playing around with the forces of darkness, summoning up malevolent spirits to move the furniture around. Mrs. Hall also thinks that her strange guest has been at another kind of spirit, the kind you find in bottles of whiskey, gin, and vodka.

This incident happens at the beginning of Chapter VI. When Mrs Hall enters the room in which the stranger has been staying, the bedclothes pulled themselves together, leaped off the bed in "a sort of peak," and then jumped over the end of the bed. Mrs Hall thinks it looks as if they have been grabbed by a hand and then thrown aside. After this, several other things begin to throw themselves at Mrs Hall: the stranger's hat, a sponge, and finally a chair. The chair "charged at" Mrs Hall, and she hears a dry laugh. This sends her running from the room, and she declares that "tas sperits." She says that she had "half guessed" that the stranger, who does not go to church on Sundays, has "put the sperits into the furniture." Essentially, she seems to think he is a sort of witch, or otherwise involved in the occult, and has somehow haunted her room.