I was trying to find a way to find nail pops in walls without hurting my eyes. The idea is to locate the nail pop and then put a bit of blue tape on it to mark its location for someone else who comes and fixes these things. And it suddenly came to me. Here we go. You will need the following:

• a flashlight
• a chair or ladder
• blue tape (painters tape) and a pair of scissors
• dark conditions (night-time is best)
• a helper who can hold the flashlight (3 year old toddlers are ok!)

All you need to do is turn off all the lights and place the flashlight almost parallel to the wall. Sweep the entire wall with the beam of light and anything popping out by even a fraction of a millimeter will stand out as clear as day. 

Once you locate a pop, ask the flashlight holder to freeze and do your thing with the blue tape and scissors, using the chair and/or ladder if necessary. Continue sweeping all walls until done.

I’ll admit this is bit hard to do for ceilings, but it works in theory.