While exploring through different reasons as to why people see these "ghosts" at night, I came across this...
One of the few things we do know for sure is that paranormal phenomena is more likely to be experienced at night, and sure enough, there is an scientific explanation for why this may be. In short, the earth is covered by a fluctuating membrane we all know as the atmosphere, which is constantly being bombarded by a strong solar wind from the sun. During the day, this membrane is at its thinnest and densest because it is being directly hit by the solar wind. However, at night, when sheltered from the sun, it expands much farther into space and has much less resistance (see illustration below). This explains why television and radio stations come in better at night, and why you can tune into stations much farther away than is possible during the day.
Therefore, the reason we see more paranormal activity at night is because there is much less resistance to every kind of magnetic and electrical current or force, making it easier for energy-based manifestations to appear. Indeed, the best time to go on ghost hunts is widely believed to be between 9 pm and 3 am, with midnight being optimal. For these same reasons, since ancient times, total eclipses of the sun have been the source of many legends and tales of paranormal occurrences.
Well, hope you enjoyed the information. It's a very interesting reason as to why these entities are only seen at night. During my search I also found some other information. I'll be posting it soon. Happy Monday, everyone!