What flaw in the front of the house does the narrator observe in the fall of the house of Usher?

the answer is not

each morning i wrote my name

on the dusty cabinet, then crossed

the dining table in script, scrawled

in capitals on the backs of chairs,

practicing signatures like scales

while mother followed squirting

linseed from a burping can

it is c through the rain, the cheetah dashed.