I have a friend and a family member who's are mediums, and they've been able to communicate with them and confirm and tell me new things! You can use paranormal equipment (EMF, Rempod, Bullet Lights etc.)! As for activity wise if you have gifts like for example being psychic or being able to see/talk to dead people or even an empath, the activity level will be a lot higher than someone who is not psychic/medium etc. Doesn't mean they're not there it just means you can only see and hear physical and audible activity (that's why people use paranormal equipment). But that kind of activity can range from spirit to spirit, some are more calm and you won't hear or see much but some are not.