Laura's trippy nightmare at around the 2:45 mark still haunts my subconscious some 30 years after this Little House aired:

If there was ever one show on television that was the least likely to induce chills it was this depression era family friendly drama. That is until 1978, when Elizabeth hit puberty and all hell broke loose on Walton mountain. Clinging desperately to her youth and unwilling to accept the inevitability of her oncoming decrepitude, the no longer adorable gingerfrau Elizabeth inadvertently invites a poltergeist to terrorize her family with sub-par piano playing, and the smashing of worthless heirlooms. Stones levitate, mirrors fog up, and radios stop working whenever the schlep-rock carrot-top is present. Finally, the tension culminates when the specter wreaks havoc at an ill-conceived slumber party. In order to dispel the presence, our war torn, copper-topped hero must renounce her childhood and own up to her gerontophobia. In the voice over epilogue provided by the always mole-faced John Boy, we are informed that the supernatural incidents were never repeated after our eumelanin-challenged heroine's impromptu exorcism.

 INDELIBLE SCENE(S): That crazy rag doll getting up and walking around!