Someone made a GPT-like chatbot that runs locally on Raspberry Pi, and you can too
(www.xda-developers.com)
Unfortunately the roleplaying chatbot type models are typically fairly sizeable / demanding. I'm curious how this will develop with more specific AI hardware though, like extension cards with primarily tensor cores + their own ram, so that you don't have to use your GPU for that. If we can drag down the price for such hardware then locally run models could become much more viable and mainstream.