In the above sentence, you may notice that 向 (향) was translated as "a long while," but I had never before seen 向 translated as "a long while," so I looked up 향하다 in a Korean dictionary and found it can mean "to face towards," "to go towards," or "to tend towards," all of which have the common meaning of "towards," but there was no meaning of "a long while." And when I looked up 向 in a Chinese character dictionary, I found that it can also mean "previously" or "recently," which is translated as 지난 번 in my Korean Hanja dictionary. When I saw that, I started wondering where Koreans got the meaning "지난 번."此宅向空, 十年無敢入者“This house has been empty for a long while, nobody has dared enter for ten years.”
The only Korean word I could think of that had 向 (향) in it and was also a reference to "time" was 향후 (向後), which means "hereafter" or "from now on." Then I realized that if there is a 향후 (向後), there might also be a 향전 (向前) since 후 (after) and 전 (before) are often paired together as opposites. Sure enough, I found 향전 (向前) in my Korean dictionary with the definition of "지난 번."
So, here is my more literal translation of the Chinese sentence at the beginning of this post:
敢入 (감입) means “dared (敢) to enter (入).” If you add 者 (자) to 敢入, you create a relative clause that means “one who dared to enter (敢入者)" since 者 means “one who.” Then by adding “無 (무)” to the front of 敢入者, you create a sentence that means “there were none who dared to enter (無敢入者)” or "no one dared to enter" since 無 can mean "there were none," "none," or simply "no."此宅向空, 十年無敢入者“This (此) house (宅) previously (向) was empty (空). [For] ten (十) years (年) no one dared to enter (無敢入者).”
The sentence seems to have come from THIS STORY, which has a rough English translation.