Why Do Ghosts Only Haunt At Night?

They don't only haunt at night, they are there all the time, but, it seems that they are more active at night because you can better see and hear their activity. Also they say the witching hour is between 12 am and 3 am. So, they will have more energy at that time.
I am sensitive to them, so I know they don't come out only at night. Hope this helps.

They are around through the day only you cant see them as they hide dark places because they dont like the light

AHA! They don't only haunt at night! If you concentrate closely, they can haunt whenever they like but they just don't like brightness so that's why you usually get more activity in the night. If you want more info, watch Most Haunted or Ghost Hunters on LIVING2 or talk to me about it. Spirits cannot harm you in any way, but they may scare you. But if you ever experience anything, just remember - be more afraid of the living than the dead.
Hope This Helps :-)
Flirta9 x

Ghost only haunt at night because during the day the strings can be seen on the blankets,the filming is easy to hide any joins or any definition .

Ghosts hunt all day but they are stronger at night.

Ghosts don't haunt at just day...  They can be seen really well on cameras in the day...

Ghosts do not only haunt at night, as everyone has said. They can be present whatever time of the day. I do believe though that they can become physical at times due to my own personal experiences. You can usually feel their presence. The hairs on your neck and arms should raise. Sometimes you feel a coldness come around you.sometimes you smell things....but they are always around, especially around 3am.  

No, ghosts do not only haunt at night. There are many haunted places that have given reports of objects flying off the shelves or being moved during the daytime in front of people. The most popular time for strong ghost activity is from 3-6 o'clock a.m in the morning which is referred to as dead time. If you have any questions, contact me.