In Vastu Shastra today, Acharya Indu Prakash tells about not keeping a broken or bad mirror in the house. Although it is auspicious to have a mirror in the house, but a broken or damaged mirror gives inauspicious results. Keeping such a mirror in the house reduces the positive vibrations and increases the negative vibrations because the light falling on the broken mirror transmits negative energy which directly affects the members of the house.
If the mirror is broken, it should be thrown outside the house. When a mirror breaks suddenly, it means that some big trouble in the house has been averted on this mirror, so it should be thrown out.