Lights without power

Hello, The ceiling lights in my bedroom will flash on with the power off? At first I thought it was a reflection of lights outside someplace bouncing off the glass of the lights, But now I have noticed it several times. My wife has also seen this. One night in the bathroom (the bathroom is also part of the bedroom) the lights got real bright and then went off. I could only see the light thru the door so I did not see the bulbs themselves. Again, I want to make sure I describe the problem correctly.
We have 4 can lights in the ceiling. With the power off on the wall switch, these lights will flash on for 1 second or so. They do not light up all the way, only dim. And
I believe that not always will all 4 come on, but I cant be sure because I am lying on in bed on my side so I don't always see all 4. All this with the power off! the house was built in 1996-97. If that helps. My email address is [email protected]