Why is my tiny ghost plants loosing its petals?

If, by "ghost plants" you mean "ghost pepper", and by "loosing its petals", you mean it's dropping its flowers without setting fruit - it's because peppers need a certain temperature range at night to set fruit. If the nights are too warm (or too chilly), the flowers drop with no fruit set. Be patient. The plant will continue to produce flowers, and eventually the weather will cooperate, and you'll get some peppers.