People get sexually aroused by different things and it varies from erotic acts to things that are not necessarily sexual. Some get aroused by body parts like feet and hair.
Although fetishes have been directly linked to mental illness and trauma; some doctors say that it is never really a predicting factor.
There is a backing theory that indicates that some people who are easily aroused sexually are more likely to have fetishes than others.
Sexual experiences during adolescence are mentioned in different studies as one of the factors that can cause fetishes.
Although some fetishes are viewed as harmless, it becomes a concern if it is on the extreme ends; especially when one feels a sense of satisfaction by causing harm to others.
Here is a confession of a man who gets sexually aroused by watching women destroy his belongings
I don’t exactly know why, but I have a fetish for watching my belongings, like my phone, iPad (+other items of technology), clothing and glasses and other things that I’ve spent time making (like Lego sculptures and drawings) being crushed and destroyed by being stepped on and walked over by woman’s shoes, especially better if my things are just left on the sidewalk and are trampled over by passing ladies who are unaware of them.