Most likely they are superstition. There's no scientific evidence to support the existence of ghosts. The stories might have been created out of the fear and the unknown that comes with being on a somewhat isolated island like Tekong Island.
While it's easy to dismiss them as superstition, some of the stories could have a kernel of truth. For example, the strange noises in the abandoned buildings might be due to natural causes like the wind or the decay of the structures, but over time, these got exaggerated into ghost stories. Also, the power of suggestion can make people believe they see things that aren't really there, especially in an environment that is already a bit spooky.
I think they are mainly superstition. However, the human mind has a way of creating mystery and the idea of ghosts can be a way for people to make sense of the uneasiness they might feel on Tekong Island. The stories might have been passed down through generations of soldiers stationed there, and each retelling might add more fictional elements to them.
A practical answer is Chapter 167, because it turns the idea into a concrete scene. The chapter opens with By the experimental field, Qi Tianyu was quite helpless as he watched Wen..., adds pressure through I'm not familiar with the others;
Look to Chapter 213 for the clearest answer. It begins with Jiang Cheng also noticed where Jiang Shixu's attention lay., keeps building through Although the corners of his mouth were still turned up, the warmth in his..., and lands on As soon as they were seated, Lin Manru picked up the public.
Chapter 210 is the strongest chapter-level answer because it starts from This was Zhao Lang's first public appearance. and follows through on Clearly, she used improper methods to get it..
The best chapter pointer here is Chapter 168, "Gu Family in the Capital". It opens with Su Yinwan spoke those words with a pitiable expression, then lowered her... and closes on The Gu Family had strict family education; even if Gu Yu was the only heir....
A practical answer is Chapter 208, because it turns the idea into a concrete scene. The chapter opens with Jiang Yan clicked his tongue, "What's this about money?, adds pressure through After the staff counted, she had a total of 22 points, which was a..., and ends on Seemingly sensing the raging.
Look to Chapter 183 for the clearest answer. It begins with Seeing that he held a blue ball identical to Su Yinwan's, Jiang Yan..., keeps building through Yinwan, it seems we're destined to be partners," he said., and lands on Hadn't this woman been relentlessly pursuing him before?.
A practical answer is Chapter 194, because it turns the idea into a concrete scene. The chapter opens with Director Sun, this isn't another one of your production team's wicked..., adds pressure through What caught everyone by surprise, however, was the arrival of this person—, and ends on Wen.
If you want the clearest chapter reference, go to Chapter 215. Early on, Jiang Li let out a light sigh and tried to adjust her posture.; later, the chapter leans on I'm not dismissing you, I just think there's no need for you to cry." Wen....
A practical answer is Chapter 205, because it turns the idea into a concrete scene. The chapter opens with Ah Fu had no idea what the video Jiang Li mentioned was., adds pressure through Let's play together from now on., and ends on Having such a sister certainly would bring happiness..
A practical answer is Chapter 210, because it turns the idea into a concrete scene. The chapter opens with This was Zhao Lang's first public appearance., adds pressure through Intermediate Repair for 15 points?!" Jiang Yan's voice rose several..., and ends on Clearly, she used improper methods to.