Yes ,it is quite normal for them to roam about, they can wander over a mile on their nightly travels, sometimes more. He/she will remember where the food was and the house.
If you can buy or make more houses that may encourage more hogs in. Planting for wildlife will encourage insects and beetles, both of which form part of a hedgehogs natural diet. Slugs/snails only form 5% of their diet..Slugs/snails carry internal parasites which they transmit to the hog, ( earthworms too ). A few do no harm to a healthy hog but if the hog gets too many - either from eating lots of slug/snails due to a lack of other foods or if the hog has suffered a traumatic event ,ie an accident or is unwell for some other reason then the parasites it has will start multiplying and attacking the hosts body. Being in captivity often causes a flare up as the hogs are stressed by being in care - then they will make the hog very ill, sometimes fatally so. If you do have a lot of slugs/snails in your garden its best to move them on somewhere else or collect them up and dispose of them. Using slug pellets should be avoided as they can also poison the hog if its eats slugs/snails who have eaten the pellets.
What food are you putting out? Quality kitten biscuits, such as IAMS or Royal Canin are good and a quality cat or dog food, preferably the loaf type. Jelly or gravy meats can cause bad tummies. Avoid the fish varieties. I also feed mine chopped peanuts, raisins, sunflower hearts, bird seeds and a little bit of fruit now and again. You can also offer chopped cooked chicken/turkey and some people give uncooked meats, chicken/ turkey or beef mince. No processed meats. Each hog is different and what one likes another will dislike.
Please do not offer milk and bread. Its very bad for them. They are lactose in tolerant and the bread swells up inside them. If eaten it can lead to very severe stomach upsets and in extreme cases can be fatal. Dried mealworms are often favoured by hogs ( but not all like them ). They contain no nutritional value and are best fed as a treat.
, I'm sure others will come - once word gets around you will probably find a disorderly queue forming . Do you have a feeding station to put the food in ? They are very easily made from plastic storage tubs ( under the bed type ), bricks and a piece of slate or tile. I can tell you how to make it if you would like to know. A feeding station will also keep cats out.
Good luck and keep persevering