some of those things make sense, getting rid of the "witchy-stuff" no, same with the priest, they're spiritually strong, but if you don't follow it, why would you call upon the spiritual leader? like asking a Rabi to help you when you're Hindu.
sage is a good idea though. it might be a build up of negative energy, in that case [which you should do annually] cleanse the house. if it's a spirit, try speaking with it to see what it wants. sometimes people hear a noise, get freaked and cleanse without speaking with the entity [if their is one] only to find out later it was there protecting the place.
there's plenty of cleansings to be found on the site, but a basic one is to clean everything with salt water and lemon. open all the doors and windows, and sweep/wash the floor starting from the middle out, say a chant, or just think 'out' or something like that. try to visualize with each stroke a white light washing away everything. finish with the sage smudge, or some protection incense, and close all the doors and windows.