Over the years, there has been a lot of chatter amongst the bloggers regarding the spirits listed in the book commonly known as the Goetia. It has been repeatedly pointed out that they will bite you in the ass, while in strict accordance with the confines of the agreement made. They take delight in such things. I have made such claims and still hold to them as factual in my experience.
I have one such spirit guarding my house. He's been heard audibly by non-magick users when someone is about to so something against the agreement I've made with him. He's kept at least one person with ill intent from entering my house. It was a repair guy that came to the door. My Gal was home alone. She opened the door he displayed a fearful expression and declined to enter the house. He simply went in the backyard and did the work he was hired to do.
The same spirit messed with My Gal's life after we broke up. I gave her my old car which she had kept running using the services of my demon. Given she and the vehicle were no longer part of my household, the spirit had a field day making her life miserable and me a bit poorer.
Some time ago, I had a roof leak. Damage was done to the ceiling. The repair folks explained they'd have to remove all the popcorn off the ceiling and then put it back up. Otherwise, the patch would be obvious. They weren't pulling my chain. It was all paid for by insurance. Uncharacteristically, I asked how much it would cost to create a textured ceiling. They told me. Uncharacteristically, I agreed to pay the mid three-digit bill. I had to pay 50% up front and 50% when done.
Oddly, the payments were spread out perfectly to hit two different pay checks. Without making a conscious effort, I spent very little during this period. So, I didn't go into debt or diminish my savings. I love the new ceiling. As I stood there admiring it, I heard, "You're welcome" from my guardian. I had asked him nothing except to keep the repair folks honest and to make sure they did a good job.
I am pretty sure the guardian manipulated me a bit to improve my and 'his' house. No harm. No foul. No debt. This is my kind of home improvement.