Try eating a little bit. Then, walk around a lot. Eventually, your Sim's Sanity diamond will decrease to the point where you fail in chatting, flirting, or imitating against another person. In the house you bought, go into the music room. The ghost will scare you, making your Sanity diamond decrease. Afterwards, after your diamond is all the way decreased, your Sim will fall on the floor and feel strange, which will make you start from your new house. You will get thrown over the fence of your house, but will feel better afterwards. It will take 500 Simoleons to get you back on your feet, and you will lose all your Sanity points.