Silverfish thrive in damp conditions, particularly bathrooms and kitchens. They like dark unfrequented places where they will be undisturbed and are attracted by sweet sugary substances. They can often be seen scurrying away when you switch on a light in a dark room.
In terms of control, they succumb to insecticidal sprays and sugary poison baits, but the essential thing is to treat the leakage that provides them with the humidity they need. Damp could be the result of poor ventilation or leaking pipes and dehumidifiers and heat will also help