One of the most misunderstood things I see during interior inspections is wall ghosting.
Dark streaks on walls. Shadows around studs. Smudges near ceilings and vents.
Someone almost always says the same thing:
“That’s mold, right?”
Sometimes it is.
A lot of times, it isn’t.
Knowing the difference matters — because the response is very different.
What “Ghosting” Actually Is
Ghosting is a discoloration pattern caused by air movement and temperature differences, not biological growth.
It typically shows up as:
- Vertical lines on exterior walls
- Shadowy outlines that follow framing
- Dark streaks above baseboards
- Smudging near ceiling corners or vents
The pattern usually matches stud spacing almost perfectly. Mold doesn’t care about stud layout. Physics does.
The Candle Connection Most People Miss
One of the biggest contributors to ghosting is candles.
Scented candles, especially paraffin-based ones, release fine soot particles. Those particles float through the house and settle where air slows down — usually on cooler surfaces.
Studs conduct temperature differently than insulation bays, so soot sticks there first.
I’ve inspected homes where the owners swore they “barely burn candles,” but every room had one on a shelf.
It adds up.
A Real Inspection Where It Wasn’t Mold
I inspected a home near Jackson where the buyer was convinced the dark streaks on the bedroom wall were toxic mold.
The pattern was textbook:
- Even spacing
- No texture change
- No moisture readings
- No odor
- No surface growth under magnification
The homeowner burned candles daily and had poor air filtration. This wasn’t mold — it was soot following airflow patterns.
Cleaning and filtration solved it.
When It Isn’t Just Ghosting
Here’s where people get into trouble: assuming all discoloration is harmless.
Mold usually shows:
- Irregular shapes
- Blotchy or fuzzy texture
- Color variation (greens, blacks, whites)
- Elevated moisture readings
- Often a musty odor
If moisture is present, mold becomes a real possibility — especially on exterior walls or near bathrooms.
A Case Where It Was Something More
We inspected a home outside Bolivar where wall staining initially looked like ghosting.
But moisture readings told a different story.
A slow plumbing leak inside the wall cavity had been feeding microbial growth. The pattern wasn’t following studs — it was spreading organically.
That’s when “just discoloration” turns into a real defect.
Why Thermal Bridging Confuses People
Studs conduct heat differently than insulation. That temperature difference causes:
- Condensation
- Particle attraction
- Visible shadowing over time
This is called thermal bridging, and it’s why ghosting lines often look so clean and evenly spaced.
Mold doesn’t draw straight lines.
How I Differentiate During an Inspection
I don’t guess.
I look at:
- Pattern consistency
- Surface texture
- Moisture readings
- Thermal behavior
- Location relative to airflow
- Household habits (candles, filters, ventilation)
Context matters as much as appearance.
Why Overreacting Can Cost You
I’ve seen buyers panic over ghosting and spend thousands on unnecessary mold remediation.
I’ve also seen people ignore real moisture problems because someone told them, “It’s probably just candle soot.”
Both mistakes come from not understanding the difference.
What Buyers Should Take Away
Not all wall discoloration is dangerous.
Not all wall discoloration is harmless.
The key is identifying why it’s there, not just what it looks like.
The Inspector’s Bottom Line
Walls tell stories — but you have to know how to read them.
Ghosting follows structure and airflow. Mold follows moisture and opportunity.
My job isn’t to label everything scary or dismiss everything casually. It’s to figure out which category it belongs in — so the response is proportional, informed, and actually useful.
