Looks like a juvenile black rat snake.
They have that spotted look and turn black as the mature. If you inspect the Western or Black rat snake closely as adults, the spotted pattern can still be seen. The prairie rat snake has that pattern all of its life. They are some of the good guys, harvesting rodents as the main food source. Perhaps you are not as happy with it in your home. But it may mean you have its favorite food in your home and need to set some mouse traps.