Buying a house can be an exciting, as well as a very anxious period. There is always the chance that you will discover a high-price problem once you move in. And sellers aren't immune from those feelings. There is nothing worse than a home inspection uncovering a problem that could convince a prospective buyer to walk away unless you fix it.

It is common knowledge that buyers should arrange for a home inspection by a qualified inspector before closing the deal. But sellers could also benefit from an inspection before actually putting the house on the market, especially if they suspect there may be a problem.

"They can call a home inspector to check the house," said Frank Lesh of the American Society of Home Inspectors. "The only thing they have to sell is the inspection service because they don't do repair work. If nothing is wrong, fine. But if there is a problem, the inspector will tell you."

Here's a short list of possible problems that could lead to expensive repairs.

OUTDATED OR FAULTY ELECTRICAL SYSTEMS

There probably aren't many houses around with outdated knob and tube wiring, where ceramic knobs hold the exposed wires in place. But if it is in a home, it needs to be replaced.

Some symptoms of potential danger in modern electrical systems include dimming or flickering lights, especially when a large appliance like the compressor in a refrigerator kicks in and the lights dim. That is a sign that the electrical system in the home can't handle the demand placed on it.

"Your nose is a good tool," said Dan DiClerico, a housing expert at HomeAdvisor. "Any faint burning or unusual smells require further investigation." HomeAdvisor is a service that matches homeowners with contractors. The costs mentioned in this article are from HomeAdvisor.

Minor problems can be fixed for $100 to $200, but a full-scale rewiring can cost $3,500 to $8,000 for an average home, more for larger homes.

First the bad news: Asbestos is a known carcinogen and until about 1980 it was part of dozens of building materials. The good news is that most asbestos is in a safe form. Asbestos is dangerous when it becomes airborne and you breathe in the fibers. Some products that may contain asbestos include some types of vinyl flooring — the tiles are usually 9 by 9 inches — insulation on boilers, furnaces and steam pipes and acoustic ceiling tiles, among others.

"If the seller knows about it, they have to disclose it to the buyer," said David Barthold from the Ridgewood office of Coldwell Banker. "It has to be encapsulated so that it does not become airborne.”

"As long as it is sealed and encapsulated it does not pose any danger," said DiClerico. "In fact, trying to remove it, may create an even greater hazard."

Any kind of removal should be done by a certified asbestos abatement contractor. Costs for removing insulation from a boiler and exposed pipes can start about $2,000. But large complicated jobs can run as high as $15,000 to $30,000.

Mold is everywhere, and most of it is harmless, even beneficial. But black mold is a health hazard and the one that gets all the press lately. Mold needs something to feed on, such as cellulose products, like wood and paper, and moisture. The most common scenarios are leaks behind walls and flooding.

By the way, don't think you need to live on the banks of a river or down the shore to worry about flooding. "About 25 percent of flood insurance claims are from homes that are not in high-risk areas," said DiClerico.

Mold is not only a health hazard, it can lead to structural repairs. "Mold on ceramic tile can be cleaned off and the grout resealed," said Lesh. "But if it is on drywall, the roots of the mold are in the drywall. You can clean it off the surface, but the mold will grow back. The only effective solution is to cut out the infected drywall and replace it with new material."

"The mold, and asbestos, companies we use are licensed by the state," said Barthold. "It is up to the real estate agent to advise the client to hire licensed, qualified companies. No job is worth playing games with peoples' health."

Mold remediation for small areas will cost about $10 to $25 per square foot. But large, hard-to-get-to areas will cost more. Cleaning heating and cooling systems, which require special tools and techniques, can run $3,000 to $10,000.

Most concrete foundations have small cracks that are the result of the curing process of concrete. They are usually not a problem. But larger cracks can be a danger sign. "Wider, deeper cracks, say about 3/16 of an inch can be a concern," said DiClerico. "When you stick a pencil in the crack and it covers the exposed lead, that could be a problem."

In most cases, the homeowner should monitor the crack to see if it gets larger. But any signs of buckling or bulging is a red flag that there is a structural issue.

Concrete block foundations are sensitive to pressure. "Step cracks, where there is deflection from one course to another indicate a problem," said Lesh. "Horizontal bulging of blocks is another serious sign."

To correct foundation problems a structural engineer may recommend buttressing the walls or pouring additional footings. The source of the problem also needs to be corrected. In most cases, the source is water affecting the foundation. "Sometimes something as simple as redirecting downspouts or re-grading the area around the foundation can correct the problem," said DiClerico.

The average cost to correct foundation damage is $4,000 to $10,000.

Other potential big-ticket repairs include: